At the age of 40, Weir knows a thing or two about remaining at the top of your game in the latter stages of your career and his experience could be invaluable for the Scottish champions at Old Trafford.
And the defender, although well aware that every player within United's ranks will be dangerous, believes that the more experienced campaigners could be the ones to watch in the much-hyped all-British encounter.
Weir said: "Scholes and Giggs have been fantastic. Their careers at the top level and the consistency they have shown and desire is amazing.
"To play at a club of this size is difficult and to do it for the whole of your career is an unbelievable achievement. They pop up at big moments and influence the game and change it.
"You cannot praise them too highly. They are United's most dangerous players because they have seen it all before and know what it takes. It is great to have that in your dressing room."
Weir signed on for another season in the summer and admits he has even surprised himself as Rangers prepare for the crunch clash.
"I never thought I'd be back as a 40-year-old but these are the places you want to play," he said.
"It is a great occasion for us and one we are looking forward to. This is a new team and a new challenge. This team still has a lot to prove.
"You couldn't ask for a harder game anywhere in Europe or in the world probably. It is going to be difficult for us and it will be a big test. We are looking forward to it."
While some Rangers players will be experiencing Old Trafford for the first time, Weir is familiar with the venue from his Everton days and concedes most of those memories are not ones to cherish.
"It was always very difficult," he said.
"Manchester United attack you and they keep attacking you and that seems to be what you've got to get used to.
"They are always very difficult games. Personally, being honest, the majority of the time you end up losing. I've managed to get a couple of draws but they are definitely in the minority."