May this be a testament to the relief ace system. Percival earned less money by signing on and therefore becoming the Rays closer. A job he did very well until suffering a multitude of injuries that ranged from his back to his hamstrings. In fact, Percival was spotless his first 11 appearances with the Rays and allowed only three baserunners while striking 10 out. From then onwards, Percival pitched 34.6 innings, walked 26, gave up 27 hits, nine homeruns, and struck out 28.
Yes, he finished with 28 saves, but so what? On his way to becoming Todd Jones reincarnate Percival also had numerous blow-ups on the mound with Joe Maddon and failed to appear during the Rays playoff run. Yet this was the veteran presence that made the Rays click? As Percival's health went, so did everything else, except his BABIP, which remained at 0.168. That's a benefit of only giving up hits that leave the playing field.
If Percival retires he'll leave a little more than four million on the table. There's no guarantee he will, but the Rays should hope he does, for financial and performance reasons.