City have endured a horrible run over the past week, losing against Liverpool twice and local rivals Manchester United once.
Merson believes City’s woes will continue against Tottenham at Wembley on Saturday.
Merson told Sky Sports: “I don’t see how City pick themselves up. They look like they are out on their feet and the last place they want to be going is Tottenham.
“They look tired and the manager has also tried to be clever a few times and changed things. Against Liverpool they needed to win by three goals and they had the best attacking right-back in the world playing in a back three. For me Sergio Aguero has to play as well.
“Pep Guardiola sides have faded in the last few years. At Bayern Munich he lost in the semi-finals of the Champions League and with Man City last season they had a bad run towards the end. It’s alright having the ball all the time but they are passing and moving, which is tiring. A lot of their players have played a lot of matches.
“I think he got the team wrong at Everton the week before they played Liverpool. The team was too strong. The league was done, they should have rested everybody and if they lose then they lose. I think there have been a few bad decisions in the last month or so and that’s where it has gone wrong.
“They have been great but if they lose this game it has fizzled out a bit and they haven’t shown that real grit too many times this season to turn things around.”
Merson predicts Tottenham to win 3-1 against City.
