As I see it usually only four strikers can see enough action in a season (cf. Yorke, Cole, Ole, Sheringham).
These two are certain to be part of the first team:
(1) Rooney
(2) Berbatov
Who do you think will fill the 3rd and 4th spots?
I cannot imagine that a player of Michael Owen's seniority will be loaned out. When healthy Owen probably will be on the bench for United. So (3) is Michael Owen.
That means that there is really only one opportunity for playing time with the likes of Hernandez, Wellbeck, Macheda and Diouf looking for a spot. None of these players would benefit from sitting in the Reserves for another season, so three of them should be loaned out for the sake of the club and the players.
Hernandez might seem to be the choice to stay because of his age, Phelan's comments, and his confidence coming off the World Cup, but both Wellbeck and Macheda have more experience of life at the club and in English football. How well will Hernandez adapt to the Premier League?
For me Wellbeck has looked a little lost in matches when he has started, but Macheda has always looked sharp. I think it is a difficult decision as to which player, Macheda or Hernandez should be loaned out. Personally I'd like to see both preferred over Michael Owen's declining form, but I don't think that would happen.