Manchester United manager Jose Mourinho has taken a swipe at Bayern Munich, saying it's impossible to buy rivals' best players in the Premier League like the German champions often do in the Bundesliga.

Bayern have made a habit of signing players from their chief title competitors Borussia Dortmund in recent seasons, a concept that may not be too foreign to longtime United fans.

But Mourinho says the increased competition in the Premier League in recent years has made the ease with which Sir Alex Ferguson brought players to Old Trafford a thing of the past.

"That is the new football. When previously you were speaking about Sir Alex Ferguson's time, this is not Germany," Mourinho told English newspapers in quotes published on Saturday night.

"In Germany, Bayern Munich start winning the league in the summer. They go to Borussia Dortmund every year and buy their best player. One day they go there and get Robert Lewandowski. The next year, they go there, Mario Gotze. The next year they go there, Mats Hummels. So they win the league in the summer.

"Do you think I can go to Tottenham and bring two Tottenham players to kill Tottenham? I cannot. I cannot go to Arsenal and bring the two best Arsenal players. I cannot go to Chelsea and bring two of the players that I love very very much. That time is over.

"That time is over so the situation of starting being champion by attacking your direct opponents in this country is over. It is over and if you get a player from these clubs, you get a player that club does not want to keep. You cannot hurt any more your direct opponents.

"Obviously Real Madrid sell who they want to sell, Barcelona sell who they want to sell, Bayern Munich sell who they want to sell, Paris Saint-Germain sell who they want to sell. So then it is more difficult to have a very good market."

Earlier, Mourinho had also spoken of a need for players to break out of their "comfort zone" and adopt a winning mentality, and asked if he had enough "winners" in this current team, the coach said: "No, of course we don't have enough.

"The ones with a history of success where that belongs to their natural habitat, Wayne Rooney, Michael Carrick, who else? Zlatan Ibrahimovic, but not in our club, Antonio Valencia and not much."

As for this year, United enter Sunday's game at Leicester City 17 points behind Premier League leaders Chelsea, and Mourinho admitted a title is no longer conceivable this season, while saying his side will fight to win both English cups and the Europa League.

"We cannot win the Premier League, that is very obvious," Mourinho said. "I don't know how many points or matches Chelsea have to lose or victories we have to make in a row, but in another three competitions we can win. We have to fight for these competitions."

However, Mourinho insisted he doesn't consider a season a failure just because the title is out of reach, saying "No, not at all. I do not measure success this season on being champions, which we are not going to be."

Still, he acknowledged that his legacy at Man United will be determined by the trophies he wins.

"I am a legend in my clubs," Mourinho said. "I am a legend in Porto, in Inter, in Chelsea. I belong to their history. In Real Madrid, I belong to their history, Manchester United I belong to the history... but the history is made by the numbers. It is made by the number of trophies."