Small picture, Mark Teixeira's continued wrist problems are a nuisance but not the end of the world. He responded well to the first bit of rest and the cortisone shot and was able to come back and be relatively productive for the last 2 weeks (.259/.328/.463 in 59 PA) in a time where the middle of the Yankee batting order has been without some of it's important bats.
Big picture, it could become more of a problem if allowed to turn into something that lingers. Teix has been productive this month, but not nearly to the degree that he was in July. His power is down, he isn't walking as much (8.2 %), and less than 3 weeks after the initial injury he's back to experiencing the same pain and inflammation as before and missing games. It's starting to look like this is something more than just inflammation and soreness, and Teix playing every day can't be a good thing for it. He said he originally hurt himself on a swing, so I imagine it can't feel too good for him every time he swings the bat. All the initial tests showed no structural damage to the wrist, but what's to say that he isn't doing damage to it now or at least risking damaging it. Is it really worth the risk of having a broken Teixeira in the playoffs or even losing him to not treat this injury properly?
Not to me it's not. Use some of the same logic the Yankees have used with CC's injuries. With the way the rest of the team is contributing and the lead they have in the division, why not put Teix on the 15-day DL to really heal? Let him give the wrist some real rest, not just 3 days, give him a chance to get some real treatment, and see how it feels after that time off. Nick Swisher, Eric Chavez, and Casey McGehee can handle the first base duties for 2 weeks. With the collection of position players they have right now, the Yanks actually have solid roster flexibility, and they could probably play .500 ball and not lose much of their division lead while Teix is out.
There's still a lot of baseball to be played this season, and still a fair amount of years and money left on Teix's contract. Giving him a few days here and a few days there and shooting his wrist full of cortisone doesn't sound like a treatment pattern that's going to lead to good things for Teix this year in terms of his performance down the stretch, and possibly in the future of his career if some damage is done. Teix is getting to the age where injuries start to linger (ask A-Rod), and letting him start to become one of the perennially walking wounded hurts his value for the remainder of his contract.
Just give him the time off. See what happens. If a few days of rest and a shot gave him 2 decent weeks, 15 days of rest and some consistent treatment should give him a helluva lot more. Teix is too important to risk for the games that count more than these. I want his bat in the lineup in October, as healthy as it can be. And I don't want to start penciling him in for future DL trips for his wrist for the rest of his career.