Paul Pogba suffered a hamstring injury during Tuesday’s Champions League win over Basel, and missed United’s comprehensive 4-0 victory over Everton at Old Trafford on Sunday.
The club have yet to announce how long the France international will be out of action for, but Mourinho has been quick to pour cold water on suggestions he might be unavailable for up to three months.
Mourinho said: “I don’t know if it is 12 weeks or 12 days. Any comment or rumour is totally wrong.
“The player was diagnosed initially after the match because of the conditions of the muscle.
“The decision was one more week to wait to see clearly in the scans. Nobody in this club spoke about 12 days or 12 weeks. It’s complete nonsense information.