Sir Alex Ferguson has announced plans to allow "one or two" players to leave Manchester United at the end of the season to freshen up the squad.

United look set to miss out on a fourth consecutive Premier League title as they go into the final weekend a point behind Chelsea, and their Champions League hopes ended with a quarter-final exit to Bayern Munich.

Many believe United need to add new options in attack, with Dimitar Berbatov in particular coming under fire. Ferguson has repeatedly defended the £30.75 million signing from Tottenham, but he was unhappy with his team's "careless" finishing at Sunderland this weekend and added: "Dimitar could have scored four."

Ferguson has not named any of the players he expects to move on this summer but Berbatov and goalkeeper Ben Foster appear to be among the candidates as the manager attempts to freshen up his team.

"You have to take a decision about where we can improve the team," he told MUTV. "When you are challenging for four trophies, it can have a draining effect.

"You have to be aware of that and spot the moment when it is time to freshen up one or two players. It is not a desire to do it but you need to do it because the demands and pressures on players can, over time, be quite exacting."

Ferguson believes, however, that there is already a wealth of young talent available for next season and suggested that major changes will not be necessary.

"People don't recognise that we've signed three players for £20 million already," he said. "Young Chris Smalling from Fulham has signed for us, Mame Diouf has done well, and Javier Hernandez from Mexico will join us after the World Cup.

"Those are three young players whose futures are guaranteed at this club. There are others who come into that bracket like Jonny Evans, Federico Macheda, Gabriel Obertan, Danny Welbeck and Darron Gibson, so we have a good nucleus and foundation of players who can carry the club for a long time."

Ferguson's comments come after United chief executive David Gill's confirmation that they are already in the process of planning further arrivals.

"I can look you in the eye and tell you straight that we have the transfer funds available to the manager," he told the Manchester United Disabled Supporters Association magazine. "Targets have been discussed already, but it's not our style to talk about names and it never will be."