Is there any need for Robin van Persie to start at the Emirates on Sunday afternoon? Manchester United's number 20 scored the excellent hat-trick that sealed the club's 20th league title on Monday night against Aston Villa, and might be given a guard of honour by the Arsenal team that sold him last summer.
But Van Persie still has an affection for Arsenal, respect for their supporters (see his non-celebration in the reverse fixture) and has constantly underlined his gratitude towards Arsene Wenger. There's no particular reason for Van Persie to be involved this weekend, and it wouldn't be a surprise to see him left out of the starting XI.
Van Persie's hat-trick against Villa also saw him move ahead of Luis Suarez in the race for the Golden Boot and with the Uruguayan suspended for the rest of the season (even an appeal is unlikely to cut the ban in half), Van Persie has effectively secured that award, which was probably the only reason he might've wanted to play.
While the Dutchman has largely remained injury free over the past two campaigns, he's still a player that needs to be rested whenever possible.
Besides, Ferguson might prefer to give playing time to squad members that haven't been regulars this season: Javier Hernandez has been a brilliant supersub but insists he prefers to start matches, while Danny Welbeck's tactical intelligence has been useful, but he needs to score more. He hit the winner in this fixture last season, and is probably a more logical starter than Van Persie.