Mourinho said this ahead of his side’s Premier League clash with Southampton on Saturday evening.
Speaking on how many players United will sign in January, Mourinho was quoted by Metro UK as saying: “Honestly, I don’t think we are going to sign anyone.
“If we do, I would say one player. I don’t see us going more than that.”
Mourinho added, “Is Manchester United by its history, by its dimension, bigger than Tottenham? I think everybody would say yes.
“Can you buy Tottenham’s best players? No, because they don’t sell. They are so powerful that they can say no.
“A few years ago, who was Tottenham’s best player? Michael Carrick. And a few years later, who was the best player? Berbatov.
“Can we go there now and bring Harry Kane? Dele Alli, (Christian) Eriksen, Son (Heung-min) here? No. So who is more powerful now? Them or us?
“I know that we have to do better than we are doing, absolutely, but one thing is to do better and another is to compare ourselves with what Manchester United was in the past because it’s impossible.
“Not just because Manchester United was fantastic, but because there was a big difference to the others and now it is not like that.
“Before the smaller clubs were almost begging the big clubs: “Get my best players. I need to sell. Please, you are powerful. Buy my best player.”
Mourinho’s men currently sit on seventh positions on the Premier League table with 21 points from 13 games.