Romelu Lukaku may not recover in time to return to the Manchester United squad to play Juventus, Jose Mourinho has admitted.
Lukaku was dropped for last weekend's win over his former club Everton and did not make the 18 for Saturday's 2-1 comeback victory at Bournemouth in the Premier League
The striker has been enduring a poor run of form, having not scored for United since the middle of September, and could miss the Champions League trip to Turin due to injury.
United face the Serie A champions on Wednesday and Mourinho cannot be certain whether the Belgium striker will be ready to travel.
"I have to wait until Monday," said the Portuguese after Anthony Martial and Marcus Rashford struck in Lukaku's absence at the Vitality Stadium on Saturday.
"He needs these couple of days. It was something in training. We don't know, a muscle problem, and we have to wait a little bit."
United have kept just one clean sheet in the Premier League this season and their leaky defence was regularly exposed by Bournemouth.
But Mourinho claimed his side's open back line is a symptom of a more aggressive style of play compared to the tactics he used in last term's second-placed Premier League finish.
"Because the approach was much more defensive and with a much more defensive approach you can hide better your weaknesses," said Mourinho.
"So when the team is really defensive and you have a more defensive mind then you base the work on that, then the team doesn't develop enough in other areas but the team managed to get results based on that.
"I'm trying to find a balance where we develop the team in the second and first phase of attack and we develop the talented players that we have without losing the balance. When we are in control we have no problems, when the opponent is in control I think the team has problems.
"But it is fantastic to have this feeling that it doesn't matter the result, we know the game is not over. It doesn't matter how many minutes until the end of the game, we have the feeling of anything can happen and, even missing chances like we did in the second half, chance after chance after chance, they keep going until the end. And that is a fantastic quality for the team."
Bournemouth dominated the first half and Eddie Howe praised his side despite the Cherries surrendering an advantage earned by Callum Wilson's 50th goal for the club.
"It's a tough one for us," he said. "I think a lot of the aspects of our game were really good, especially during the opening period. We passed the ball well and there was really good intensity to our play.
"We were disappointed at half-time that we weren't winning and we felt that we deserved to be leading by more than one. We knew the second half was going to be a different game.
"Manchester United changed things and made substitutions, but I was pleased with my players attitudes to the game and they gave everything to the match.
"It was one of the best first-half performances I've seen us have in the Premier League since being promoted. I can't fault anyone in terms of effort."
