David Moyes' United are being given little chance of upsetting Bayern Munich in their UEFA Champions League quarter-final, with the first leg at Old Trafford on Tuesday.
With regular left-back Patrice Evra suspended, Buttner is expected to be given the big job of minimising Robben's impact.
The Dutch full-back is excited about the prospect despite facing arguably the world's best player.
"I feel confident about playing them. I know what Arjen Robben can do and I'm ready for him. I've watched him so I know how he plays," Buttner said.
"I've never played against him before and I haven't watched videos or anything like that to study him, but I know enough from what I've seen to know how he plays the game.
"He's very good one against one, especially when he comes inside. I have to focus on that game and be confident in my own quality. I know I can get the better of him.
"It's not under discussion how good he is, we all know that, but this kind of big game is why you play football. It's what it's all about."
Buttner is unlikely to remain at United beyond this season and the 25-year-old is eager to show what he is capable of against Bayern.
"It's a big game on Tuesday, but it's a chance for me to show what I can do," he said.
"It's been vital for me to get the two matches, because it would have been difficult not to play and that to have to face a big game like Bayern.
"I probably still need a bit more, but two games should be OK. After that I hope I can get even more matches."
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