Spurs tackle David Moyes' side on the back of a morale-boosting home victory over Stoke but face a rejuvenated United who are on the back of a run of six straight wins in all competitions.
"I like to play with risk," said the Tottenham manager, whose side beat the Potters 3-0 on Sunday.
"There is going to be, with respect to Stoke, tougher tests ahead and we know that.
"We have to try to find the right formula to perform against some of the bigger teams.
"We have to assess what Man United are coming with. We know they're going to be very, very good.
"They always are and have been ever since I was in football. We know we have to give them respect but we can't be lambs to the slaughter.
"We need to make sure we go out there and impose ourselves on them as much as we can."
West Brom, Everton and Newcastle have all shown it is possible to do that this season, with all three winning league matches at Old Trafford.
In fact, United have only won four of their nine home matches and Spurs head to the north west buoyed by last term's 3-2 victory.
"They're turning it around and they are on a run," Sherwood said. "We know from history when they are on a run, they get a head of steam and are very hard to stop.
"We've got to try and find a way of stopping them in their tracks to get something positive for ourselves.
"We won last year there. Gareth Bale scored a great goal, so they've already been there and imposed themselves on Man United. Hopefully they can use that as an experience to go forward.
"It is a big arena, a fantastic football stadium but it will only be nice if we get a result."