Ralf Rangnick has explained Cristiano Ronaldo is currently struggling with a hip problem amid questions over his future at Manchester United.
The Red Devils legend was notably not included in the matchday squad for the FA Cup third round tie with Aston Villa at Old Trafford.
It comes after reports over the weekend claimed he has held "crisis talks" with agent Jorge Mendes about the current state of the club.
Although Ronaldo is said to be frustrated with life under Rangnick and sceptical about their chances of winning silverware, it is not those claims which have led to his removal from the team.
When asked about his star man, the interim United boss told MUTV: "I spoke with Cristiano yesterday before training, he told me that he’s had some problems for the last couple of days.
"Minor problems, but in the end, we decided that it made more sense to not take any risks in a game that could easily last 120 minutes, so we just decided to rest him, not play him at all."
Rangnick was then asked by BBC Sport where Ronaldo would be, to which the German replied: "I suppose he will be in the stadium but he had some problems with his hip, with his hip muscle.
"And we just decided that it would be better for him not to play this game. I don't think it's anything serious.
"He's told me that he's had that problem for the last couple of days. Again, in a cup game when you can play 120 minutes, I thought it would be better to not take any risks."
Questions have been raised about Ronaldo's relationship with Rangnick as is he said to have made it clear to the United board that he wouldn't want to see him appointed permanently.
Further reports have detailed the mass discontent amongst the first-team squad, with as many as 17 players said to be unhappy with their position at the club.
Ronaldo could depart come the end of the season depending on who United appoint to take over from Rangnick for next season.
He seems eager to finish his glittering with more silverware, and a report from France has claimed Paris Saint-Germain could offer him a route out of his current predicament.