Manchester United will be hoping for good news on Paul Pogba after he limped off in Tuesday's Champions League win against Basel.
Jose Mourinho believes his French midfielder could be out for a "few weeks" with a suspected hamstring injury after lasting just 19 minutes and leaving Old Trafford on crutches following the 3-0 victory.
Goals from substitute Marouane Fellaini, Romelu Lukaku and Marcus Rashford made it a comfortable night for Mourinho on the pitch but Pogba's condition will be a concern with a hectic schedule over the next month.
Pogba will undergo scans on Wednesday with Mourinho expected to provide an update on his injury in Friday's news conference ahead of Sunday's Premier League match game with Everton, live on Sky Sports.
Speaking to MUTV after beating Basel, Mourinho said: "I don't know (what the severity is). I just know from experience it's a muscular injury.
"In my experience, muscular injury stops you from playing for a few weeks, I think. It looks for me too (like a hamstring injury) but I haven't spoken yet to the medical department.
"Squads are for this, squads are for injuries, squads are for suspensions. We don't cry with injuries. So if no Paul for Sunday, we have (Ander) Herrera, we have (Michael) Carrick, we have Fellaini and we have (Nemanja) Matic."
Pogba has enjoyed a fine start to the season, scoring twice in United's opening two Premier League games.
United, top of the Premier League table alongside neighbours City, will almost definitely be without last year's £89m signing when they host Everton and a returning Wayne Rooney who left the club in the summer.
Mourinho expects United to be more switched on at the weekend, having been irked by the "PlayStation football" United started with as they took their foot off the gas at 2-0.
Paris St Germain, Bayern Munich, Chelsea and Barcelona all scored big on the first night of the Champions League group stage, but Mourinho believes United are in the "second level" of this year's teams.
Asked if smaller sides were getting weaker and the big teams more powerful, Mourinho added: "I think the Champions League for these teams you speak about and for the Real Madrids, and the Barcelonas, and Bayerns, I think the Champions League starts in February.
"Now is just the warming up and in February when us English teams are trying to survive after the winter period, they are fresh and ready after this warm-up.
"For them, this is a warm-up. I think we are in the second level and the second level is let's qualify, let's make the points to qualify for the knockout phase.
"When you do that, if you do that, let's enjoy to play against the big guys."