Michael Carrick says the season with David Moyes at Manchester United "just didn't work" as he prepares to face his former manager on Nissan Super Sunday.
The Scotsman, now in charge at Sunderland, took over from Sir Alex Ferguson in May 2013, but only lasted ten months at Old Trafford - the shortest managerial tenure in the club's history - before being sacked in April 2014.
During his stint at the club, United failed to qualify for the Champions League for the first time since 1995 and finished outside of the top three for the first time in Premier League history, with Carrick conceding it was a difficult period for the club.
"It was a tough time. I think we can all say that with Sir Alex [Ferguson] leaving and the changes that happened after that. It was a tough season, there's no getting away from that," he told Sky Sports News HQ.
"We had some success in the Champions League and we weren't too far away from getting past Bayern in the quarter finals so it's fine margins I think. When you look at it, it just didn't work that season and we didn't have a great season in the end.
"Unfortunately for David, he lost his job so I'm sad how it finished but I suppose that's football. If you don't get the results, and you're the manager, you suffer for it.
"I don't know, to be honest [if becoming United boss after Ferguson was an impossible job]. It's obviously a tough job, he [Ferguson] is arguably the greatest manager of all time.
"So of course it was going to be a tough job to take, but whether it was impossible or not, I'm not sure. I wasn't sitting in that seat and I wasn't in the position to be manager. You'd have to ask him I suppose.
"Just because it's tough times, it doesn't mean there's fighting and you don't get on or not like each other. Sometimes things just don't work out for many different reasons and that was the case.
"He's got a lot of his former players from here and Everton so that shows there's a respect there. Sunderland are obviously having a tough time at the moment but they still have some quality players there.
"You're almost waiting for them to go on a run of results - hopefully it's not on Sunday - but that's football. There are ups and downs and they have the experience in there that they will pull on to try and turn things around."
There have been two permanent United managers since the departure of Moyes three years ago, with Jose Mourinho the man currently at the helm at Old Trafford.
United have had mixed success under the former Chelsea and Real Madrid boss, winning the EFL Cup in February and still in contention for Europa League glory with a trip to Anderlecht in the quarter-finals on Thursday.
They are sixth in the Premier League table - four points off Man City in fourth - and Carrick is sure that Mourinho will bring success back to the club.
"You can see that Mourinho is a winner and he's won wherever he has been. You can see that it drives him on and it's all about winning and rightly so," the midfielder added.
"That's what you want, you want to be winning things and be successful. We're still a bit short in the league but we won the EFL Cup already and we're going for another one. He's driving for that and he's hungry, you can see he's hungry for more and he wants more success.
"It's the same with any manager [around the training ground], you speak to him at certain times and it's no different. There's no special formula if you like, you're creating relationships on a personal and professional level.
"I think it's a respect thing more than anything. Obviously to respect the players and for us to respect him as a manager and his coaching staff and to get the right balance. I'm sure he will bring success whether it is this season or the next or the one after, whenever it is, he will bring success."
As for Carrick himself, he has a testimonial coming up to mark his tenth year at Manchester United and with one year left on his current deal at the age of 35, the subject of his future is in the horizon.
"It won't be anywhere else in England [next season], no. I've had too many good times here to do that elsewhere," he said.
"I've said it for a number of months now, I'm just really enjoying playing football. When you get to this age and you come closer to the end, obviously you get asked these questions but I'm just trying to play and compete in the team and be part of the squad and see how long that takes.
"I feel fit at the moment and we've got such a busy time, I haven't really given much thought to it, I've just been playing and concentrating on what we can achieve this season. Anything else can be sorted out in good time.
"In some ways you do [try to enjoy every moment], and in some ways it's just what I've always done. Of course, around the corner, you're thinking about how long you've got left but then you come in to training and go about your business exactly in the same way.
"Whether I play on Sunday or not, it's the same thing. Obviously I have a bit more experience to pull on so you understand situations but it's business as usual really."
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