If Teixeira does not change his approach to hitting, his career is finished.
Oh, he will still be playing first base for the Yankees, but his usually offensive production will significantly decline. And that massive contract won’t be looking so good anymore. His playing time will be based upon his contract and defense, and less upon his ability to hit.
And this is not some random “small sample size” garbage either. Teixeira has been on the down slope since he signed with the Yankees, especially in the areas of batting average* (ooh, that terrible stat), and on base percentage* (the really good stat, right?).
*It’s funny how many sabermetric guys discount batting average and how it is “meaningless.” But doesn’t batting average compose the largest portion of hitters’ on base percentage? Usually, when formerly productive hitters OBP declines, it is usually due to a lower batting average, rather than walk rates, which are pretty consistent for established major leaguers.
Teixeira’s decline actually began during the World Series title year of 2009, a title which Teixeira was a big part. His batting average has declined from .292 in 2009 to .256 in 2010 and .249 last season. Subsequently, his OBP have been .383 (2009), .365 (2010) and .343 last season. He hit over .300 with a .400 OBP the prior two years, so the decline started in 2009. Teixeira’s walk average** is consistently around .090. His slugging percentages have also dropped, with his last two seasons being the only years since his rookie campaign where Teixeira has not slugged over .500.