The Red Devils will play on Thursday night in London after facing Southampton at Old Trafford on Monday.
"The next two weeks will be hectic but then again we're fit, very fit - our lads have not felt as fit as this for years, I'm sure," Solskjaer explained.
"It was a big thing towards the end of last season that we felt our team wasn't fit enough, we got a few injuries, this season we've not had that kind of a problem.
"It's not going to be a problem and a concern for us but 24 hours, 48 hours is a big difference at this time [of the season] so we've not been handed four Aces, to put it that way, for the last two weeks. But we're going to have to put on a poker face and play the cards well."