MLB players who could retire after 2016

Aoki struggled through a concussion in 2015 and hasn't been himself offensively this year, hitting only .245 and successful on only four of 11 stolen base attempts. There might not be a market for him at age 35 next season.

Colon continues to prosper in his mid-40s throwing his fastball almost exclusively. At some point one would think the decline would come, but it hasn't arrived yet.

Crisp has seen a slight rebound after battling injuries last year, but he's still hitting only .227 and much of his speed is gone. Likely a free agent after this season, Crisp is unlikely to find work easily at age 37.

Ellis's veteran leadership is more valuable than his play on the field. He's hitting below the Mendoza line for the second time in three seasons and could opt to start a coaching career if the decline continues at age 35.

Knee issues have hindered Hamilton for several years and prevented him from playing this season. It remains to be seen if he will have anything left next season, when he turns age 36. If Hamilton's career is over, he had quite a run with five All-Star appearances and the 2010 AL MVP.

Morneau is hoping to return from elbow surgery this season, and the White Sox signed him in hopes that he can return. He was productive as recently as last season with the Rockies, but it remains to be seen if he can come back from his latest injury at age 35.

The odds are against Nathan returning from his second Tommy John surgery at age 41, but the Cubs signed him just in case he can. An elite closer in his prime, Nathan made six All-Star appearances.

Ortiz is in his swan song this season, announcing that he will retire after 2016. He's as productive as ever with an OPS above 1.000 nearly three full months into the season.

The 35-year-old Peavy got off to an awful start and has been playing catch-up recently. His ERA is 5.47 through 14 starts with a big velocity decline.

Pierzynski looks to be on his last leg at age 39, and a broadcasting career could be in his near future. He's hitting only .194 while sharing playing time with Tyler Flowers.

Qualls was hoping to be a setup man for the Rockies this season, but he's struggled with an ERA well above 4.00. Most telling is his 10 strikeouts in 21.1 innings.

Ramirez had almost no market this offseason, struggling to find a one-year deal with the Padres. He's having his worst year at age 34, with a .616 OPS.

Rodney has revitalized his career at age 39, allowing just one earned run through 26 appearances. There will certainly be a market for Rodney if the trend continues, but he might consider going out on top.

A-Rod's future is really up to the Yankees. He's due $21 million next season but hasn't done much to earn his money this year at age 40. He's hitting only .215 and has also spent time on the DL.

Ross plans to retire after this season, but he's going out with a bang. He's having one of his best offensive seasons in years, with an .803 OPS as Chicago's backup catcher.

Ruiz hasn't done anything offensively since last season, and he's played sparingly behind Cameron Rupp in Philadelphia this year. His defense is still valued, but his skills are waning as he approaches 40.

Shields is signed through 2018, but his career could be cut short if the recent trends continue. His ERA is now above 6.00, and he's allowed 21 earned runs in 8.2 innings since being traded to the White Sox.

It's telling that Simon was recently demoted to the pen considering he's on a team desperate for pitching. His ERA is above 9.00 at age 35.

Ichiro is playing his best baseball in years, recently surpassing Pete Rose's hit record when taking into account his Japanese League hits. He's set to reach 3,000 hits in the majors soon, and while he's still performing at age 42, it remains to be seen how much more baseball Ichiro wants to play.

Thornton has had a great career as a left-handed reliever, but he's really struggling this year in San Diego with an ERA just below 5.00. Approaching age 40, his playing days are winding down.

Uehara was demoted to setup duty this season after Boston traded for Craig Kimbrel. He's struggled to keep the ball in the park but has still been very effective at age 41. Still, a long history of injuries bring up questions on how much longer he can pitch.

Uribe has struggled offensively as Cleveland's starting third baseman, with a .658 OPS. He struggled to find work this offseason and might not have the versatility for a bench role any longer.

Utley got off to a quick start for the Dodgers, but his offense has predictably slowed recently. He's still seeing plenty of playing time but needs to maintain his numbers and remain healthy.

Vogelsong was pitching well in limited time before getting hit in the face by a pitch and suffering facial fractures. With a 4.59 ERA since 2013, it remains to be seen what kind of opportunities Vogelsong will see next year at age 39.

It's been one arm injury after another for Wilson since last season, and he's approaching free agency after this year at age 35. He hasn't been healthy enough to pitch this season, and it remains to be seen what he will show if and when he does return.