MANCHESTER -- Jose Mourinho has told Zlatan Ibrahimovic and Romelu Lukaku that no one is guaranteed a place in his Manchester United team.

Ibrahimovic, who has re-joined United on a one-year contract, was Mourinho's first-choice striker last season. But after the 35-year-old was released in the summer following knee surgery, the United manager sanctioned a £75 million move for Lukaku as a replacement.

Mourinho does not expect Ibrahimovic to be available until January. But he insists once the Swede is fit, he will pick his team on form rather than price tag or reputation.

He told a news conference on Friday: "Zlatan knows me. And he knows that I play the players that I think are the best for the team. I always did it.

"I always did that in my life so if he comes here and he proves that he is the best, he plays. If the other ones don't give him a chance to prove that, that's life. But I try always to be honest with my players and with my team. I try.

"Maybe sometimes I do not do the correct things. But I always try to do."

Mourinho has not ruled out the possibility of playing Ibrahimovic and Lukaku together in the second half of the season and insists it was an easy decision to bring the forward back.

He said: "I see Zlatan important for the team. I just say that my squad is better for sure, he is one more option, he is one more striker, he is one more experienced player, one more player that can play nine or 10, that can play double strikers or no, there are lots of matches to play.

Zlatan Ibrahimovic has opted to rejoin Manchester United this season. AP Photo/Dave Thompson

"If we progress in the Champions League and if we progress in one of the two cups, I don't even say both, if we do that we are going to be in the position where we couldn't do it only with Lukaku and Rashford, especially if I play both together.

"We are going to be a better squad and I give you just one example -- if we play Stoke on the weekend and two days later we play against Burton and I want to give a rest to my two strikers, who do I play against Burton? I have to play Rashford or Lukaku.

"I don't have another one to play so I cannot give rest to my players, I cannot do rotation with them like I am going to do with the midfield players or the central defenders or with the wingers.

"He is one of the best strikers in the world so the only consequence of it is we are going to have a much better squad.

Mourinho is still looking for a another signing to go with Lukaku, Nemanja Matic and Victor Lindelof, although he admits it may not happen before Thursday's transfer deadline.

The deal for Ibrahimovic, however, has removed the need for the 54-year-old to ask executive vice-chairman Ed Woodward for a new striker in January.

He added: "I need a striker, so probably in January I would be knocking on Ed Woodward's door asking for a striker for the second part of the season and I don't need to. I have one of the best in the world.

"Everyone knows I would like a fourth player and I can't hide that because I had it in my mind, but I am happy if I am not going to have [a fourth player] and I don't think I am going to have and I was the first to tell my board not to feel any kind of pressure from me in that respect.

"But probably next summer, I have to try to get a player for a position that I think can make us stronger."