Spurs travel to Aston Villa on Sunday before facing RB Leipzig in the Champions League and then to Stamford Bridge for a crucial top-four game in the Premier League.
"He can play everywhere: at no.10, no.8, midfield player with Winks, on the right, on the left... everywhere," Mourinho said.
"I'm so, so happy with him. I like him very, very much."
There were concerns over Lo Celso's fitness this week but Mourinho confirmed the Argentine is fit.
"We are no more limited to [Steven] Bergwijn," Mourinho continued.
"Juan Foyth is still out a little bit and apart from [Moussa] Sissoko and Harry [Kane] we're fine. The situation is getting better for us at the right time because we have lots of matches.
"We had a good week [after the winter break]. Three very good training sessions. Of course, if we didn't play Southampton we would have been back earlier so we had less time for training but we had three very good days, going through different aspects of our game, trying to improve them."