Five for Friday: Rafael Nadal out of Miami; Roger Federer closes on No. 2

Five For Friday is an end-of-the-week roundup of interesting tidbits from my notebook. This week looks at ongoings in Miami, including Rafael Nadal's withdrawal.

Rafael Nadal withdrew from the Sony Ericsson Open on Friday, citing tendinitis in his left knee. (Getty Images)

Nadal withdraws from Miami: Those darn knees have foiled him again. Just hours before he was set to take the court to take on Andy Murray in the semifinals of the Sony Ericsson Open, Rafael Nadal announced his withdrawal from the event due to tendinitis in his left knee, which had grown worse with each day.

I've seen quite a few commentators and pundits roll their eyes to Nadal's knee complaints this week and I've never really understood the cynicism that seems to be growing around Rafa's injuries. Yes, he told a nutty tale in Melbourne about feeling horrible knee pain before the tournament, but when he was asked about his knees afterwards, Nadal insisted he felt perfect and that the pain was gone. In Miami however, Nadal was consistently concerned with his knee, calling the trainer for tape and seeming noticeably distracted by the injury. So the withdrawal shouldn't be a complete surprise.

It's a wise move from Nadal, who has no business risking further injury given the Olympic-tightened 2012 schedule and the upcoming clay swing. With Nadal unable to defend his finalist points in Miami, he'll head into the clay season with a 900-point lead on Roger Federer. That's a comfortable lead, but not an unsurmountable one given Federer's relatively early exits in Monte Carlo (quarterfinals) and Rome (Round of 16) last year.

And how's this for some perspective. According to Andrew Burton -- the best Federer expert for my money -- Nadal earned 590 points for the final stretch in 2011 (after the U.S. Open), compared to Federer's 3000, and in 2012, Rafa's earned 2010 points to Roger's 2855. Sometimes objects in the rear-view mirror are closer than they appear. Rafa, this is not one of those times. Roger's on your tail.

Charleston situation: When the WTA Roadmap was introduced in 2008, the primary goal was to provide a mechanism to guarantee top player participation at the big events. You could understand why that's necessary for the function of the WTA Tour: Tournament directors needed to understand exactly what they were paying for and the WTA needed a means to deliver. By and large, the Roadmap has worked. Top player participation increased 24 percent by the end of 2011 at the nine Premier events and withdrawals were down 18 percent. In turn, the tour has been able to secure more investment and the Premier tournaments have continued to grow in both stature and prize money.

But the Roadmap has rankled a few feathers recently, namely in the Caroline Wozniacki camp. Wozniacki, who has built a career on playing more tournaments than most of the top women, raised eyebrows in Indian Wells when she called for more flexibility in the tournaments the top players can play.

"It's tough to go head-to-head against the top players all the time," Wozniacki said, referring to the top-flight Premier tournaments. "Sometimes you want to play a tournament you're not allowed to. Sometimes you do not want to play a tournament and you have to."

Why is Wozniacki dissing the Roadmap? She's annoyed that she isn't being allowed to defend her title in Charleston next week at the Family Circle Cup. I've seen a lot of hand-wringing from fans and writers criticizing the WTA, claiming the Roadmap is somehow unfairly restrictive in locking out a defending champion since there are now stricter guidelines to locking player fields. It states that Premier 700 tournaments must have two top six players, or one top six player and two top 10 players. Once that benchmark is hit, tournaments are free to fill the field, which makes it more challenging for top players to parachute into tournaments closer to the start dates.

But here's the thing: Wozniacki never signed up to play Charleston. Any top player who committed to the tournament before the start of the season would have been allowed to play. Wozniacki herself chose not to return to defend her title and once she realized her year wasn't going as well as she hoped, she tried to get in but the field had been maxed out.

That's tough luck for her and the tournament, but this could have all been avoided if she just committed before the season began. There's still an outside chance she could get in (i.e., if another top player withdraws), but here's something to remember: By refusing to commit from the get-go, Wozniacki didn't give Charleston an opportunity to use her in marketing the tournament. That's not a small loss. Advance commitments have a huge impact on sponsor and ticket sales, and ultimately, the health of the tournament and tour. If players think they can drop into any tournament they want as the year plays out and avoid advance commitments, that can cripple the tour.

Odesnik advertisement: If you've been watching the Sony Ericsson Open on Tennis Channel, you may have noticed a regularly recurring ad featuring a player who might look vaguely familiar. The ad is for Genesis strings, and it features one Wayne Odesnik -- yes, the man who was suspended for one year after pleading guilty to importing HGH into Australia in 2010. Quite frankly, the ad makes my skin crawl. Why would an equipment company film an ad featuring a guy who is resoundingly disliked within the tennis community and connected to banned performance enhancing substances?

Well here's one way to look at it: Had anyone heard of Genesis strings before now? Probably not. So step one of Marketing 101 -- brand awareness -- has been accomplished. Now who wants to buy some strings from a guy who's ranked No. 113 in the world and has ties to HGH? Please form an orderly queue.

Rafa steps down: Busy news week for Rafa, which is not how he likes it. Nadal announced earlier in the week that he had stepped down from the ATP Player Council, saying that he no longer had the energy to commit to the Council and he wanted to focus on his tennis. But from Nadal's public statements as well as the behind the scenes grumblings, it's clear that Nadal grew frustrated with what the Council, which is headed up by Roger Federer, was able and willing to do. One of Nadal's pet projects has been to overhaul the ranking system from one that is based on one year of results to two years. By Rafa's logic, that would mean players would feel less pressure to play through injury in order to defend points and protect their ranking, and would thus lead to a healthier tour.

Nadal's frustration actually gives me more faith in the Player Council. The idea of a two-year ranking system is so bad I have a hard time understanding how he thought he could ever get it through. Under the Nadal system, you wouldn't see the rapid ascents of Milos Raonic, John Isner, or Juan Martin del Potro. Players wouldn't be able to climb up the rankings and make a name for themselves in quick fashion and that's just bad for the sport. The tour needs new blood and needs to keep players hungry. Tell them that winning a few tournaments in a row won't do much to change their ranking and it takes away a lot of the motivation. Aside from that, a two-year system would actually encourage withdrawals from top players. Right now they suffer fines and a loss of points if they skip tournaments. Take away the immediate impact of a loss of points and I bet that the top guys would be more than happy to pay their penalties if it meant a longer break.

Streak no more