Manchester derby: The biggest match for Man City - and Man Utd have a chance, says Paul Merson

Sunday's Manchester derby, live on Sky Sports, is "Manchester City's biggest match", says Paul Merson, but he believes Manchester United have a chance to cause an upset.

Pep Guardiola's side have won just one game in their last 10 in all competitions. They lost to Juventus in the Champions League on Wednesday evening, leaving them with plenty of work to do to even claim a top-24 finish in the league phase.

It comes ahead of a huge game on Super Sunday as Man City welcome Ruben Amorim's Man Utd team to the Eithad. The Portuguese's former side, Sporting Lisbon, beat City 4-1 just last month before he departed for Old Trafford.

United, though, have lost their last two Premier League games to Arsenal and Nottingham Forest as Amorim looks to turn around the club's fortunes.

Chatting to The Football Show, Sky Sports pundit Merson gave his thoughts ahead of the big game...

Over the last few years, it hasn't been Man City's biggest game. No disrespect to Man Utd, but when they've played Arsenal or Liverpool, those have been their biggest matches.

But this weekend, this is their biggest football match. This is a huge cup final.

Man Utd kept Arsenal very quiet at the Emirates a few weeks ago. If they can do that this weekend, I think they've got a chance. I'd go [Marcus] Rashford, Amad [Diallo] and [Alejandro] Garnacho up front and play pace, skill and guile.

There's not a lot of strength between those three, but they have the pace on the counter-attack to cause Man City major problems. If it goes that way, I can see Man City having a difficult day.

But I never go against Man City, even on this run. They've got too many good players.

It's hard now. When Man City really started hitting the heights, each player was a £60m to £70m player. The player who was backing up a player was £50m or £60m, but that can't happen at the moment with financial fair play.

So, for me, it is going to be a problem. I don't buy into the older players [being a reason for a dip in form], I think it's confidence more than anything. Only six months before, they were embarrassing teams with their passing and movement.

Their confidence is low and it's hard to play like Man City do. Pep Guardiola has probably never been on a run like this since he started playing football at six years of age. This is real unusual territory for him and he's got to cope with it.

Against Crystal Palace, he's bringing on [Jeremy] Doku and [Jack] Grealish in the 80th minute when [Matheus] Nunes and Savinho weren't doing anything. He could have made those substitutions at half-time and that worries me.

When you're struggling, you panic and make bad decisions both on the pitch and in the dugout. We're seeing bad decisions and bad choices in the dugout at the moment. Sorry Pep.

The Rodri factor is definitely taking its toll, he knits it all together. If you were reading a book on holiday and they've won the league so many times, won the Champions League, won the treble, going for the quadruple.

Then you turn the page and the following season, one game in 10 and lose seven, you'd throw the book in the sea and say 'how's that ever going to happen?'. It's just mind-blowing. I never thought I'd see this happen.

But I liked what he [Pep Guardiola] said [after the defeat to Juventus] - it's gone, move onto the next game now and they've got to go on a run. They beat Forest and you thought it would start and it hasn't.

I live my life a day at a time and they've got to live theirs a game at a time. They've got to start with the Manchester derby, win that and move onto the next one.

It's hard to forget about the games that have just gone, though, because they're the ones that affect your confidence. Because you're not winning every week, your confidence goes.

They need [Mateo] Kovacic back now. He's not the solution but at least he gives you a bit more in midfield. At the moment, they're finding it difficult to win the ball back and that's their problem as well.

It's fine having nice players in there but, in midfield, you've got to win the ball back. That's an absolute must.

If they get eliminated in the Champions League, I'm not swimming in the sea to get that book back out. I can't see that happening.

I see them beating PSG and the big advantage is that it's in January. If that's played next week, then it's a bit different. There's all the games over Christmas and some players back from injury.

I don't see them not qualifying and you'd be bang out of luck to get Man City over two legs as well. You wouldn't expect to be playing Man City in that group [the knockout play-offs], you'd expect them to be in the top eight.

I've always said Man City are a team that turn it on in the second half of the season, they win 13 or 14 games on the trot and they've done that numerous times.

I don't see that happening this year. I watched them against Crystal Palace and usually if they draw that game, the goalkeeper is the best player on the pitch and Crystal Palace have ridden their luck and were hanging on.

It wasn't. They were having a go at Man City and trying to get that goal. I know they [Man City] had 10 men for the last bit, but that just covered over the cracks. Teams are having a go at Man City at the moment.

I'm not sure Amorim is looking for his best XI yet, I think he's just trying to see who he can rely on.

By the end of the season, he needs to know who is going to be there, who isn't going to be there and who he wants to bring in. Otherwise, Man Utd are going to be also-rans and we don't want that.

Man Utd are one of the biggest clubs in the world and that's what he's trying to do. I don't think he's worried about his best team at the moment, he's just trying to see who's going to be there and who's not because there's players who have been there for a while and haven't done anything.

I don't know who is going to buy him [Marcus Rashford]. It's a problem. Someone said PSG would buy him, but if I was PSG, I'd think 'Man Utd are struggling like mad, and they want to sell one of their best players and biggest threats' and that tells you something.

If they are trying to get rid of him, his wages carry so much, it's unreal. If you're PSG or someone, why aren't you trying to get the player Man Utd are trying to get instead of him?

I don't see how they are going to get rid of him with those wages, and they won't get £60m, £70m, £80m for him.