Ibrahimovic played a major role in Manchester United's success last season, scoring 28 goals as the club won the EFL Cup and Europa League - returning to the Champions League as a result.
He has trained with the club during his rehabilitation though, and Mourinho has made it clear he still believes the forward can do a job for him.
The 35-year-old was released at the end of the season, but a new contract is being discussed.
"You know, he's injured, he needs time to recover", the United boss said. 'He is not ready to play tomorrow.
"It's not something urgent, that we are desperate to have it done or not done".
United have moved to replace the Swede in this summer's transfer window - bringing in Romelu Lukaku from Everton, but the possibility of the striker linking up with the club again seems a formality given Mourinho's latest comments. "I'd say seven teams to fight for the title and 20 teams to fight for the victory every weekend, every match". Victor can play right-back and can play central midfield.
Mourinho still speaks of free agent Ibrahimovic as part of the group, saying he is injured for the start of the season along with other "important players" like Luke Shaw, Ashley Young and Marcos Rojo.
"Between the players we have lost and the players we have got, I think we are in a similar situation, but with more experience of working together and a much better pre-season".
"We got a central midfielder, we got a striker".