In the third inning of the Washington Nationals spring training contest against the New York Yankees, Russell Martin hit a soft grounder up the right side that Chien-Ming Wang fielded. As he ran to the bag to tag it for the out, his left ankle appeared to turn, causing his knee to buckle, and sending him to the ground. The Nationals said it was a left hamstring strain. It was the last thing the Nationals wanted to see this spring.
The Nationals pitching staff has been widely regarded as one of the best in baseball, and Wang's potential to be an outstanding part of the back-end of that rotation may have been set back with Thursday's injury. Wang was throwing his sinker harder than he did last year, and he had command. He gave up two hits, walked none, and struck out four in just 2 2/3 innings of work.
Many assume that John Lannan will slide into the fifth spot in the Nationals rotation if Wang ends up on the disabled list, but that may not be an automatic move. The Nats have a lot invested in Ross Detwiler, who is also a lefty, throws harder, has a higher potential than Lannan, and is out of options.
The spring outings thus far also work in Detwiler's favor. We all know that players don't care about stats in spring training, but Lannan's line this March has been pretty damning, mostly as a result of Thursday's appearance. In four innings, he gave up six runs (four earned) on seven hits and a walk, resulting in some rather unimpressive numbers: a 1.89 WHIP and 14 hits in just nine innings pitched. Meanwhile, while not perfect, Detwiler is looking at an impressive 1.17 WHIP and just six hits in 7 2/3 innings so far this spring. In his last outing, Detwiler got knocked around a bit but was sawing batters off left and right.
Despite all of that, if I was a betting man, I'd imagine that the two-time Opening Day starter, John Lannan, would end up with the Nationals on Opening Day if Wang ends up on the DL. He has the tenure with the team and has the option to be sent down once Wang gets healthy or if he doesn't meet expectations. If that happens, Detwiler will get a chance to shine in a starting role once again.
Remember, nothing is guaranteed here. Wang may still end up with the Nationals in April, and it might be just a minor tweak. We don't know any details yet. The Nats will surely prepare for the worst case scenario, though, and you can bet that Lannan's and Detwiler's next starts will be looked at with extra scrutiny as Opening Day draws closer and closer.
In terms of investment, I would argue to say that the team actually has more invested in Lannan.
The issue is that he is being paid $5 million this year, but based on WAR, many people value him at about $2.5 million, so other teams view him as vastly over priced. The only way they can move him then is if he pitches and pitches well. If they stick him in the bullpen, he becomes even MORE overpaid.