Roma have warned Manchester United that midfielder Kevin Strootman is not for sale despite the Netherlands international being continually linked with a move to join Louis van Gaal at Old Trafford.

Van Gaal has made no secret of his interest in Strootman, who is closing in on a return from the cruciate knee ligament injury which forced him to miss the World Cup.

However, Roma are unwilling to bow to United's interest and general director Mauro Baldissoni says Strootman will remain at the Olympic Stadium in the immediate future.

"We can't wait to see Strootman back on the field, because we really miss him and that moment is getting closer," the Roma chief told Sky Sport Italia.

"We are proud to have Strootman in our squad and he is not for sale."

Though Daley Blind joined United from Ajax on deadline day, Van Gaal appears to be keen on improving the club's resources in the January transfer window, with the club linked with a £25m move for Strootman.

With Michael Carrick no closer to returning from an ankle injury picked up in pre-season, United are lightweight in the middle of midfield and Strootman would likely be required to fill that void and succeed the England international.

United made six significant summer signings, however Bayern Munich boss Pep Guardiola says the club were unable to afford any of his players during the summer.

But Van Gaal, speaking prior to the 5-3 defeat to Leicester City, says he has no doubt big-name players want to move to the 20-time Premier League champions despite their absence from the Champions League.

"Every player I have contacted wants to play for Manchester United," Van Gaal said.

"In spite of the fact that we are not playing in the Champions League this season, the players are still willing to come. It is unbelievable but it is because of the greatness of this club. They all believe in the project we have started now but I will say again that it has only just started. It still needs time."