28 is still younger than the vast majority of FA's. If it's a 6 year deal then he's signed through age 33 (well, would turn 34 a few months before the contract ends), which isn't bad at all. Given the age and how the Cubs avoid post-prime years like the plague (and rightly so) the Cubs will want him more than a 31 y/o like Chapman unless Chapman comes on a lower AAV and only on, say, a 3 year deal, which probably doesn't happen anyways.