The OP is spot-on. Mauer makes it clear he does not lift weights, nor does he do much training at all. Stretching is a benefit, but it's only a complement to strength training, agility, training, etc. All of the people on here saying that squats, deadlifts, cleans, etc. don't make a difference in athletic performance must be people that have never lifted themselves. Look at Mike Trout; you think he would say that strength training has improved his game? There's no question. It's not that Mauer needs to bulk up, but lifting weights would absolutely have preserved his athletic abilities for a longer period of time. As others have said, that photo of his gut while playing golf says it all.