Strange how it’s not a problem when Foden is on the left wing. Couldn’t have a better left back to link up with and receive great passes. It’s fairly rare Walker actually overlaps on the other side as he tends to sit as Cancelo is allowed to roam. Lack of pace and left peg is a big problem for Jack out there not who’s playing left back.
This is my own opinion. Happy to discuss. But I think that it is more about the preferred foot. Grealish competed with Sterling on the left wing, not Foden.
Foden is left footed. He is a traditional left winger - left foot on left wing. Grealish is an inverted left winger - right foot on the left wing. So Foden has no crossing problem playing with Cancelo. B
Same thing happened in England when Southgate played Foden on the right wing. Since England's right back rarely overlapped as well- Foden looked not as good as he did for City usually.
Thus it is actually not fair to say that Grealish takes Foden's time because they are not the same kind. It is more fair to say Grealish takes Sterling's time on the left wing. Because they are the primary inverted left winger in the squad. Foden and Stones invited and persuaded Grealish to join City when they played in England last year.
When Pep wants a traditional winger on the left side to cross, he picks Foden (for example Liverpool, Man utd). Because these team have problem of protecting the space behind (Liverpool high line and Man utd laughable defending)
Chelsea is very very good at protecting the space behind. Even if you put a lovely cross like Foden/Grealish/Sterling did several times yesterday. Chelsea defenders would make sure other City players not on a better position than them. So the crossing were not that dangerous as it looked to the audience. You would find all better positions were taken by Chelsea defenders first. Unless we have a very good striker who is physically strong enought to be able to get to the better position facing Chelsea CBs - those crossing are likely to end up with nothing.
On the other side, Man utd poor defenders are not well trained. Even they tried to play 5 persons defending like Chelsea, they did not really know where the city players were when we attacked in waves. So they would either hurry to try to clear the ball and resulted in worse situation like own goal when we crossed - or forgot to clear the ball and resulted in Bernado's goal.
Pep played an inverted left winger on the left wing facing Chelsea. The main task was gaining as much as attention - rather than crossing. Thus an inverted wing back who could cut inside - suited the best. Kante had to move to protect Azp to provent the cutting inside route. If a traditional winger was played there, Rudiger would protect the space behind and you cannot tire Rudiger out in 90min.
Thus we saw that Grealish and Cancelo played all their slow tricks on the left wing. Kante rushed there to help AZP. Then Kovacic had to move to the central. Grealish/Cancelo would only pass the ball back to Rodri when they saw Kovacic made the move. Then we shifted the ball to the right and let Sterling run quickly at Alonso. Kovacic had to run back to protect Alonso and Sarr. Time after times Kovacic burnt out - made an error in the 1st half and gave us a golden chance (Grealish SHOULD put it in the net). Then in the 2nd half, Kovacic and Kante were even more slower and Kovacic tracked back way too slow to protect the central space and KDB shot comfortably. Pep's master plan won again.
Pep played a very similar plan in CL final. Deployed an inverted left winger - Sterling. However the problem was on the right side it was Mahrez - an inverted winger. Thus Chelsea defenders did not need to move and rotate that much. You need to have an inverted winger + a natural winger to play this trick. Thus in the following 2 games, Pep used Grealish + Jesus and Grealish + Sterling. And it worked well for us. Given Mahrez was away, there were only Sterling/Jesus available on the right wing, both natural winger. Thus it had to be Grealish to start on the left. IF Grealish was still with covid, I guess Pep perhaps started Jesus on the left + Sterling on the right.
It is not about who is better - but who is more suitable.