Under The Knife: Fatigue takes its toll on catchers ... or does it?

Publish date:

My baseball tour came to a close on Tuesday, leaving Cincinnati after a six-day trip through four baseball towns. The one constant, besides baseball, was the heat. It got me wondering whether high temperatures were having an affect on the games. The catchers take the worst of it, so I had crack researcher Dan Wade look into it. His findings were surprising:

With the injuries to star catchers such as Joe Mauer, Buster Posey and Carlos Santana in the last two seasons, the topic of moving hot-hitting catchers out from behind the plate has come up with some frequency. One reason often cited for the moves is "the wear and tear of the position," a phrase that doesn't seem to have a distinct meaning. Certainly it includes things like collisions at the plate, foul tips and blocking balls in the dirt, but there seems to be an underlying belief that catchers are so heavily taxed in the normal performance of their job that it causes them to tire more quickly than players at any other position.

Looking at the average monthly on-base percentage for catchers over the last three full seasons, we see the trend we'd expect to see if catchers really did experience accelerated fatigue. Their OBP starts at .328 in April, falls to .326 in May, then slides to .313, .308, and .305 from June to August. September, however, breaks the pattern; catchers saw their OBPs rise back up to .319, their third highest monthly mark. This 'dead cat bounce' could be due to pitcher fatigue, but another factor could be a decrease in the quality of pitchers faced, as teams use expanded rosters to give minor leaguers experience in the majors. Catchers walk more and strike out less in September, which lends some credence to the idea that they aren't facing the same quality of opposition.

The entire topic of fatigue bears more study, though teams continue to do a poor job directly measuring this important factor. It is, I believe, the single most important thing teams could do to reduce injuries. Before I get too fatigued myself after a road trip, let's get to the injuries:

Giants fans panicked when Lincecum was scratched from his Tuesday start. It turns out he's just human. Lincecum had flu-like symptoms and was simply too sick to pitch. Lincecum will be fine once he recovers from the illness and gets rehydrated. There's some question about whether he'll make his next start, whether he'll be re-slotted or put in at the next available point. It's never good to be sick, but Lincecum will probably benefit from a bit of extra rest for his magic arm.

It's the ol' good news, bad news thing in New York. The Yankees will be getting Soriano back shortly. His minor league rehab is going well, despite his very first pitch being deposited in the seats. Soriano hasn't had any recurrence of pain, so he'll likely be up quickly, slotting back in front of Mariano Rivera. He could be a seventh-inning guy due to the emergence of David Robertson.

The bad news part is Hughes' velocity. In his last outing, he was back down to 91. That points to fatigue or a recovery issue, one I'd warned about. The problem that cost Hughes a portion of this season wasn't corrected; it just vanished with extensive rest. He'll need to show he can bounce back or it will become very worrisome for the Yankees rotation. Worse, if Hughes slides again in his next start, they'll have to think about shutting him down again.

With Oswalt heading out for a rehab assignment, it's time to look not only at his injury but his performance. I asked Eric Seidman and Matt Swartz of Fangraphs if their statistical tools offer any clues about how Oswalt's back is affecting things. They told me, "Roy Oswalt may have given up just three earned runs in his first 18 innings after returning from the DL, but his performance wasn't nearly as impressive. Skill-Interactive ERA (SIERA) estimates a pitcher's ERA as if he was pitching with an average defense in an average park, without good or bad luck. The metric accounts for walks, strikeouts and grounders to infer the hittability of a pitcher. Oswalt recorded only eight strikeouts in those 18 innings, and SIERA smelled hits on the horizon. Not surprisingly, over his next five starts, he recorded a 5.81 ERA and landed back on the disabled list. SIERA predicted his shiny ERA wouldn't hold up since the skills indicative of how well a pitcher performed were unimpressive. After striking out batters 23 percent of the time last season his rate has dropped to 14 percent this year. His velocity also dropped from 93 mph to 91 mph. While it might not seem like much, a 1-2 mph drop is significant and likely is a chief contributor to his drop-off in performance. If properly rehabbed, the velocity could return, and his strikeout rate should increase. Otherwise, it will take a great deal of luck to prevent runs at a rate in line with his career averages." It's that velocity loss that worries me most, so watch his velocity in his rehab start on Wednesday and his first couple starts back.

The Phillies bullpen has had issues all year, but with Ryan Madson back and Antonio Bastardo emerging as a nice option, it seems like Lidge and Contreras are just gravy. With the starters the Phillies have, they don't need depth to shorten most games, but it's going to be more important in the playoffs. Contreras is still iffy to return and is going through platelet-rich plasma injections to try to get some healing going in his elbow. The situation isn't as dire as I was led to believe earlier, but it's not good either. The Phillies are more concerned about how to best spot Contreras and whether he'll be healthy enough to risk a playoff roster spot on at this stage.

Lidge is back off the DL, throwing well, but oddly reliant on his slider. That would indicate some lack of confidence in his fastball. We'll have to see how Lidge holds up over a series of appearances and if his pitch selection continues to be so tilted. We'll also need to try to see if he's exhibiting any fatigue signs, much in the same way that we do for Phil Hughes.

It's come to this for Jones. He comes off the DL just a couple weeks after knee surgery only to strain his quad in his first game back. It's a clear cascade, but Jones' age is really beginning to show. He can't stay healthy playing a normal schedule, so the Braves need to take the next month to experiment with patterns. The problem is that Jones doesn't like experimenting. Most players are creatures of habit, but they're also creatures of pride. That combination, along with Jones' status with the organization makes it even tougher on the Braves medical staff in this situation. He'll miss the rest of the week and the DL is a possibility if there's no progress by the weekend.

Drew has a reputation as injury prone, but in the last five seasons, he played 135 or more games four of those years and 109 in the low season. That's not "injury prone" by any good definition. That said, it's been a bad week for the Drew clan. Stephen Drew is out for the season with his broken ankle and now older brother J.D. is on the shelf with an impingement in his shoulder. The shoulder has clearly been bothering him at the plate, so the Sox are hoping that the time off will help. There's talk of Josh Reddick taking over the position or of the Red Sox dealing for Carlos Beltran, so Drew's return is as much about external events as his internal impingement.

In the midst of an epic losing streak, doing the right thing with Pineda is going to be even harder. Pineda got pounded by the Red Sox last time out. It might be that he was tipping pitches, or it could be that he's hitting a wall. Look at Jaime Garcia last season and you'll see the pattern. Pineda pitched 133 innings at AA and AAA last season; it's axiomatic that major league innings are more stressful than minor league innings. While we don't know the exact multiplier, it's safe to say that at 124 innings, he might be at or above the true level of his career high in workload. Pineda shouldn't go much beyond 150 if you use the basic "rule of 30," (a notion that young pitchers should not have their workload increased by more than 30 innings per season) but it would be better to see the M's closely monitor his fatigue and recovery. At some point soon, they'll have to shut the Rookie of the Year candidate down and convince their fans that it's the right thing to do.

The Diamondbacks are losing infielders. First Drew and now Blum. Blum's finger fracture is much less of an issue than Drew's fractured ankle, but missing him for a couple weeks is going to force the team further down the depth chart as they try to hang on in the NL West. Blum should heal relatively cleanly, but he can't afford to come back with a reduced contact rate. Some have said that it's "just" his pinkie, but remind those guys that when Blum's hitting lefty, as he does most of the time, it's that finger that's against the nob of the bat and takes a lot of the force of the swing.

Late word that Brian McCann is heading to the DL. He strained his oblique Tuesday night. No word on the severity, but he's the toughest to replace for the Braves and makes a deal for another bat even more important (and possibly costly) ... Jose Bautista took a 91 mph fastball off his helmet, but came out OK. The Jays said there were no signs of concussion and expect him in the lineup Wednesday ... Dave Cameron of Fangraphs is going to be on the DL for a while as he fights cancer. Let's all hope he gets back into the game he's so passionate about and beats this ... The Mets will make a decision on where Johan Santana will pitch next on Wednesday. It's most likely to be at St. Lucie (A), though there's a chance he could throw another sim game first ... I've been underrating Johnny Cueto this year, though it does look like his ERA is a lot of luck ... Kevin Youkilis will need a couple of days to let his hamstring heal up after a mild strain hustling down the baseline. The DL isn't a big possibility ... Vladimir Guerrero should come off the DL this week after letting his hand heal up ... Trevor Bauer signed with the D'backs and will head to Visalia (A). He's very talented, but many scouts are worried about his mechanics and durability. He's on the 40-man, so he'll likely come fast, giving Arizona a possible 1-2 with Bauer and Jarrod Parker as early as next spring. Health will be the key for both ... Erik Bedard will come off the DL on Friday. He's hoping he won't have to try to stop the streak when he does ... Luke Scott is done for the season after having surgery Tuesday to repair a torn labrum in his shoulder.