Apart from these players veteran midfielder Paul Scholes is likely to retire again following his injury which kept him out for nearly a month.
Midfielder Anderson is set to leave in the summer after falling down the pecking order. The 24-year old Brazilian failed to perform to his potential since his £17million move from Porto in the summer of 2007.
Sir Alex Ferguson sees Anderson as fourth-choice midfielder behind Tom Cleverley, Michael Carrick and Ryan Giggs. Anderson has made just 12 league appearances scoring one goal.
Nani has been out with injury for the last two months, but has recovered to fight for a place in the starting XI. Nani refused to sign a contract extension and is likely to play out his contract which expires in 2014.
Javier Hernandez is finding it hard to get into the first-team with Wayne Rooney and Robin van Persie as first-choice strikers. The rise of Danny Welbeck has also dented the Mexicans chances of securing a place in the team.
Buttner, Phil Jones and Chris Smalling have been brought as long-term replacements for Patrice Evra, Rio Ferdinand and Nemanja Vidic.