Sir Alex Ferguson’s men are locked on eight points with the Portuguese giants, and a win at Old Trafford would put the English side in pole position to top Champions League Group C.
With Danny Welbeck doubtful and Chris Smalling out, Ferguson has received a boost by Rooney declaring his fitness.
“Wayne Rooney got a few knocks and missed training, but he should be OK for Tuesday,” the Scottish coach told Sky Sports.
“We’ve got one or two knocks from Saturday. Jonny Evans got a little tightness in his hamstring yesterday, but hopefully will be OK.
“Chris Smalling trained but won’t be available, but he should be OK for Saturday,” he stated.
Ferguson was under no illusions to how important the game is for United’s progression hopes, and has targeted three points.
“It’s a big game. It’s a game which we recognise is a real European game in the history of Benfica and ourselves.
“It’s a really interesting game for both teams. Both will want to win so it should be an open match and hopefully we will get the result we want,” he concluded.
By Gareth McKnight