When he's healthy, Troy Tulowitzki is arguably the top shortstop in baseball. Unfortunately, the health of the Rockies' 28-year-old star is hardly a given these days.
Limited to just 47 games last year due to a groin injury that required surgery, he started the 2013 season on a tear, helping Colorado put an early claim on first place in the NL West. Alas, he left Sunday's game against the Diamondbacks in the third inning after injuring his left shoulder in an awkward slide into home plate, and his availability going forward isn't known.
According to the Denver Post's Troy Renck, the Rockies said Tulowitzki suffered a mild strain of the rotator cuff in his non-throwing shoulder and will be re-evaluated on Monday. If he goes on the disabled list, it will mark the fourth straight year that he's missed significant time due to injury.
Such a loss would be a sizable blow to a team that ranks among the young season's surprises after setting a franchise record with 98 losses last year. At 15-10, the Rockies are tied for first place in the NL West with the Diamondbacks, though they've dropped six out of their last eight games. Four of those losses came at the hands of Arizona, who prevented them from sweeping a three-game series in Colorado last Sunday, then beat them three out of four in a series that wrapped up this Sunday; in between those two series, Colorado dropped two of three to the Braves in Denver.
Tulowitzki has been a big part of that strong start, hitting a robust .312/.398/.610 in 93 plate appearances. Both his slugging percentage and his six homers rank in the league's top 10, with the latter already approaching last year's total of eight, hit in 203 plate appearances. Though the Rockies play in a notoriously hitter-friendly environment, his home/road splits are virtually even: .324/.400/.618 in 40 PA at home, .302/.396/.605 with three homers in 53 PA on the road.
Both of those lines are a bit above his true level of talent, but not by much. In a Major-League career that began in late 2006, he's hit .293/.365/.507, and over the last three seasons and change, no shortstop has been anywhere nearly as valuable according to Baseball-Reference.com's version of Wins Above Replacement:
Tulowitzki has a sizable lead even though coming into Sunday, he had played in just 335 games in that span, compared to 429 apiece for Aybar and Reyes, 479 for Andrus and 495 for Ramirez. In fact, he's played in more than 143 games just twice — 155 in his 2007 rookie season and 151 in 2009 — and averaged a mere 120 games a year from 2007-2012. In 2008, he spent 67 days on the DL and played in just 101 games due to a left quad strain and a thumb laceration. In 2010, he missed 39 days and was limited to 122 games due to a left wrist fracture suffered on a hit-by-pitch. In 2011, he avoided the DL, but was limited to 11 games in September due to bursitis in his left hip; even so, that year's 143 games played stands as his recent high-water mark.
Last year, Tulowitzki went on the DL on May 30 and underwent surgery on June 21. Though he played eight minor league games on a rehab assignment in August and September, and appeared to be close to returning to the Rockies, he never did get put back on the active roster. By that point, Colorado didn't have much to play for; it was 20-29 when Tulowitzki went on the shelf, and things only got worse from there.
Under new manager Walt Weiss, the Rockies lead the NL in scoring at 5.08 runs per game. In addition to Tulowitzki, Dexter Fowler (.295/.398/.602 with a team-high seven homers), Wilin Rosario (.329/.346/.592 with six homers), Michael Cuddyer (.333/.402/.598 with five homers) and Carlos Gonzalez (.289/.369/.511 with four homers) are all swinging the bat well. With third baseman Chris Nelson (.242/.282/.318) lagging in production, Sunday marked the Major-League debut of 22-year-old Nolan Arenado, who ranked 52nd on Baseball America's Top 100 Prospects list this year after a solid .285/.337/.428 showing in Double-A.
The real question about the Rockies beyond Tulowitzki's health is whether the pitching staff can sustain its relatively hot start. After allowing an MLB-worst 5.49 runs per game last year, the starters are yielding a more respectable 4.33 runs per game this year, which ranks 11th in the league. Having experimented with a four-man rotation in which the starters were limited to around 75 pitches, the team has reverted to a more traditional five-man rotation this year, and while no starter has thrown more than 99 pitches in a single outing, the team has gotten quality starts in 13 out of 25 games.
Jorge de la Rosa, Juan Nicasio, Jon Garland and Jhoulys Chacin — a quartet limited to 28 starts last year due to injuries — all have ERAs below 5.00, though their strikeout, walk and homer rates are nothing to write home about; only de la Rosa and Chacin have FIPs below 5.00 (4.22 and 2.91, respectively), suggesting that hot start will be hard to maintain. Chacin, who was limited to 14 starts last year due to a pectoral injury, is back on the DL with a mid-back strain but is nearing a return. The rotation as a whole ranks 11th in the league with a 4.14 ERA while the bullpen ranks sixth in both ERA (3.31) and inherited runner scoring rate (30 percent).
If Tulowitzki does miss time, it's unclear who would fill in at shortstop. Last year, rookie Josh Rutledge took over in his absence and hit an uneven but respectable .274/.306/.469. He's now the starting second baseman, so it's more likely the much lighter hitting Reid Brignac or Jonathan Herrera, both of whom have spotted at shortstop thus far, would share the position. For now, the Rockies hope that such an assignment will be only for a few days. If not, they'll have a much harder time maintaining the pace they've set.