Manchester United boss Louis van Gaal says striker Radamel Falcao still needs to justify his place at Old Trafford.

Falcao, 28, has scored three goals since joining United in a £6m loan move from AS Monaco in the summer.

Van Gaal said: "If a player costs £95m or £5,000, it doesn't make any difference. You have to prove yourself."

The Colombia international was left out of United's squad for their 1-0 home loss to Southampton last Sunday.

He has started just seven Premier League games for United and his agent Jorge Mendes suggested that Falcao may not extend his stay beyond the end of the season .

United have an option to activate a £40m buy-out clause for the striker, who earns £265,000 a week.

Van Gaal added: "He has to prove himself, that we have agreed. We have made this deal and everything is clear and it is not the end of the year [the duration of his loan spell] so he has the chance for that.

"For the manager it is the quality of the training sessions, the quality in his performances and matches and he has to compare [favourably].

"A player of £95m has to prove himself also. Maybe he has less motivation so I have to be like that."

Van Gaal would not confirm whether Falcao would be involved in United's game at Queens Park Rangers on Saturday or whether striker Robin van Persie would be fit to play following an ankle injury.

However, the Dutchman did quell speculation of a major move into the transfer market during the January transfer window.

He said: "I don't think that we shall be very active as not many players of a certain level are available.

"When we buy a player he has to be better than the players that are playing now and that is a difficult job."