Louis van Gaal hailed Cristiano Ronaldo as a "fantastic player" after admitting he is in the hunt for a marquee signing to boost Manchester United's chances of challenging for the Champions League.
Van Gaal is hoping to mount a serious challenge for domestic and European silverware in the coming year after qualifying for the Champions League in his first term in charge.
Despite spending more than £225million since taking over, Van Gaal still thinks his squad lacks speed and creativity in attack.
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The Dutchman is therefore on the lookout for a talismanic forward who will help to put United on a par with their domestic and European rivals.
''We need still more speed in front and also more creativity,'' the 63-year-old said in an interview with the British media on United's pre-season tour of the United States.
''That is why I hope (Angel) Di Maria shall stay. But we don't know that (he will).''
When asked what kind of player he needs to make United true competitors in the coming year, Van Gaal added: ''I can give examples of champions, Bayern Munich have (Franck) Ribery and (Arjen) Robben, Chelsea have (Eden) Hazard and Willian, Real Madrid - Ronaldo and (Gareth) Bale, Barcelona have Neymar and (Lionel) Messi.
''Manchester United fans want us to compete with these teams.
''(Ashley) Young and (Juan) Mata had fantastic seasons (last year), with assists and goals, but to win the Champions League you need speed also.
''That is why I think, maybe, we still have to buy a player with speed and creativity.''
Ronaldo has maintained his status as one of the most destructive players in the world since leaving United in 2009 following six successful years at the club.
Van Gaal has been linked with a move for the two-time Ballon d'Or winner recently.
The Dutchman initially refused to discuss the idea of the Portuguese coming back to Old Trafford.
''I cannot answer this question. You can put it in another way and I shall say it the same,'' he said.
''We cannot show our strategy in buying or selling players. When we shall buy a player and he has signed then we shall say it but not in the process, not in the strategy.''
But when pressed on the matter, Van Gaal dropped his guard.
''Now, I make an exception for Ronaldo,'' the former Barcelona and Bayern Munich coach said with a smile.
''He is a fantastic, fantastic player but he knows that. I like him.''
Unless Ronaldo asks to leave Madrid, United would find it hard to sign the 30-year-old Portuguese star.
A more likely signing for Van Gaal would be Barcelona forward Pedro or Thomas Muller, although Bayern Munich insist they will not sell the World Cup winning striker.
Other than Javier Hernandez, who was loaned to Madrid last year, and 20-year-old James Wilson, the only senior central striker Van Gaal has in his squad is Wayne Rooney.
The Dutchman has already told the captain he will be his main striker this season, but he is demanding a lot from the 29-year-old.
When asked whether Rooney has to score 20-25 goals in the upcoming year, Van Gaal said: "Of course, because (Sergio) Aguero is making that amount of goals (for Manchester City)."
Despite playing Rooney in midfield for much of last season, Van Gaal has little reason to doubt the former Everton man will deliver, however.
"He is our striker. Probably he has to prove it. I have fully confidence that he shall do that," Van Gaal said.
"He is also the captain of the team so he shall play a lot of times in the striker's position.
"Normally we shall have a lot of matches so Chicharito (Hernandez) can also play in that position.
"We have still Wilson. (Adnan Januzaj) played in the striker's position. He did it very well so we have enough choices to make."