When you reach the age of 30 as a professional athlete, your days are automatically numbered. It doesn’t matter what sport is involved, it’s a similar story. In this case, it’s America’s Favorite Pastime.

After speaking to numerous athletes, they all want to play until they physically can’t anymore. Some reach a certain age where they want to hang up their cleats, and others realize they don’t have the body they used to.

When it comes to a veteran pitcher whose knuckleball helps him dominate the test of time, a couple veterans hoping to join prestigious hitting clubs this season or someone who wants to just have one more shot at the bigs, each one of these players has a story.

Here are 10 MLB players who will prove age is nothing but a number in 2017.