Rooney, 31, announced on Thursday that he is staying at Old Trafford after being linked with a move to China.
The England captain has missed United’s past three matches with a calf injury.
“He is fine, he has been training with the team,” said Mourinho on Friday. “He made his statement about staying here exactly in the right moment.”
The Portuguese added: “That should be the last question about it until the end of the season.”
Rooney’s agent, Paul Stretford, had travelled to China to see if he could negotiate a deal, although it is not known which clubs he spoke to.
However, United’s record goalscorer released a statement on Thursday saying he hoped to “play a full part” in the rest of the Premier League club’s season.