He has since started FA Cup games against Yeovil and Huddersfield and, ahead of the Champions League round-of-16 second leg with Sevilla at Old Trafford on Tuesday, he insists he is keen to play a part on the pitch between now and the end of the season.
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.
Carrick underwent a procedure earlier in the season to treat an irregular heart rhythm.
United last hosted a Champions League knockout game in 2014 and skipper Carrick says it is high time they competed again for European football's top trophy.
"I think it's pretty much already been said, to be honest with you", he replied when asked whether he was retiring. "You can't live like you've had a career before you've had the career - you've got to earn it".
Carrick, who is a former England worldwide, joined the Red Devils from Tottenham in 2006 when United's retired veteran manager, Sir Alex Ferguson convinced him to swapped White Hart Lane for the Old Trafford.
On the topic of joining Mourinho's staff he said: "It's kind of been sorted out, but we're still talking about it so there is nothing to totally confirm yet". For two or three days I was thinking am going to carry on playing is it worth it but that passed and I got fit.
'I understood after getting back fit that I wouldn't be playing as many games as perhaps I might have done, but that's something that I understood.
"I've been training hard and we'll see what happens for the rest of the season". Signed for £18 million, he has played 463 times for the Mancunians and also represented England 38 times, named in the Three Lions' squad to both Germany 2006 and South Africa 2010 FIFA World Cup tournaments but did not play a single minute.