The 18-year-old was signed by United in a £37 million deal on deadline day but has remained with the Serie A club until the New Year.
Diallo is highly rated by Atalanta but the winger has played just 35 minutes across two substitute appearances for the first team this season.
And Solskjaer claims that Diallo may follow the same path as Facundo Pellistri, who also joined United on deadline day.
The 18-year-old Uruguayan has trained with Solskjaer’s first-team squad but has not yet made his debut and is instead getting minutes for the Under-23s.
‘We felt Facundo would benefit,’ said Solskjaer.
‘He started training with the first-team – he did well but we couldn’t give him game-time so we thought we’d give him a run of games in the [Under] 23s and he’s benefited from that.
‘His confidence has been given a boost. He’s shown in all the games that he can impact the game.
‘They’re both talented players that we believe will have a long career here. It’s important we find the right time.’