Both Macheda and Diouf played in the League Cup game during the week and Ferguson believes the duo would benefit from regular football.
Despite a Macheda penalty which levelled the game against Palace, United lost the tie 2-1 in extra-time and Ferguson later apologised for his teams’ poor showing.
"The problem we have is to do with the reserve league there is now - it's really a youth league," he told the club's official website.
"That is a big problem. We'll be reviewing the whole situation in terms of how we get more games for the players.
"Loan deals work well for all the young players in terms of getting game-time and that's what we're looking at with Macheda and Diouf. They need games.
"They're young and every young player wants to play and we have to give them that opportunity."
The Red Devils will travel to Villa Park on Saturday in their Premier League clash against Aston Villa, looking to make amends for their midweek disappointment.