The 36-year-old club captain has featured sparingly for United this season, having been sidelined earlier in the campaign due to a heart scare.
"There comes a time when, as much as you don't like, your body tells you it's time to stop playing football," he said.
"That's pretty much where I'm at, which is fine."
In January, United boss Jose Mourinho said he expected Carrick to retire at the end of 2017-18 and join the Old Trafford coaching staff – a move the player himself acknowledges as his likely next step.
"It's kind of being sorted out, we're still talking about it to be honest. But it's looking likely, yeah."
Carrick joined United from Tottenham for £18million in 2006 and has played 463 times for the Red Devils.
A graduate of West Ham's youth academy alongside the likes of Frank Lampard, Joe Cole and Rio Ferdinand, Carrick went on to win five Premier League titles under Alex Ferguson.
He became a Champions League winner when United saw off Chelsea on penalties in Moscow in 2008 and, although he lost subsequent finals in Europe's top competition against Barcelona in 2009 and 2011, last season's Europa League triumph completed an individual clean sweep of major domestic and European club trophies.
Carrick, who was capped 34 times by England, underwent a procedure to correct an irregular heart rhythm, having initially felt unwell during the EFL Cup win over Burton Albion last September.
Now back in action, he is happy to be retiring on his own terms.
"It started in the Burton game and then happened again in training," Carrick added, discussing his health problem.
"I'm clear now, it took a bit of time to get over. There were two or three times when I wondered whether it was worth still playing, but I soon got over that.
"I understood that I wouldn't be playing as many games, but I've been training hard and trying to keep fit. I wanted to finish on my own terms."