Dimitar Berbatov believes the potential arrival of Erling Haaland would hamper the development of Manchester United's other young strikers.
United head scout Marcel Bout went to watch Red Bull Salzburg striker Haaland in the Champions League as the Austrian side lost 2-0 to Liverpool.
The 19-year-old has been linked with a move to a number of top European clubs after scoring 28 goals in 22 games this season.
Berbatov insists former club United should opt against signing Haaland and focus on developing Anthony Martial, Marcus Rashford and Mason Greenwood.
"[Haaland] is good and he is still young," said Berbatov, who made 149 appearances for United. "He is developing and maybe he can get better."
"But I've said many times before that Martial and Rashford are, for me, the two main strikers that Manchester United need to keep. I love them.
"I played with Martial in Monaco, I know how good he can be. Now he is in the place he can develop and become a world star.
"Everyone knows how good Rashford can be as well. He is still 22, something like that, so he still has a long way to go and he can become even better.
"So, for me, they need to stick with these two players."
Ole Gunnar Solskjaer has given plenty of opportunities to all three of United's young forwards this season.
Rashford, Martial and 18-year-old Greenwood have made 56 appearances between them this campaign, scoring a collective 26 goals.
Berbatov admits he is not sure if Leeds-born Haaland fits the mould of what United fans want to see.
"If they need to buy one more [striker], I'm not sure because Manchester United fans want to see speed, beating players, getting past players, having confidence, scoring fantastic goals," Berbatov added.
"I'm not sure that if they buy a typical centre-forward, he's going to fit into the system. I forgot about Mason Greenwood as well.
"I said it before, if you buy someone, the players will be like, 'wait a minute, I'm young and if you buy someone it means you don't trust me.'
"They need to stick with these young players because they have so much talent. Just nurture them, show them the right way and they'll be fantastic."
How to follow the January transfer window
Sky Sports will bring you the very latest news from the January transfer market with the return of three shows.
Start your day with Good Morning Transfers at 9am as our team of reporters bring you the latest news and insight. Transfer Talk then follows at midday delivering analysis of the biggest stories. Then join us at 7pm for the definitive round-up of the day's news with The Transfer Show.
Meanwhile, the Transfer Talk podcast will also be back at the turn of the year with more expert analysis from here and across the continent.
And as well as tuning into Sky Sports News, don't miss a thing with our dedicated Transfer Centre blog.