The pair formed part of Roy Hodgson's attacking trio behind Daniel Sturridge for their opening game against Italy - as England went down 2-1 in Manaus.
While Rooney supplied an impressive cross for Sturridge's equaliser, he endured a mixed game overall, leading to further questions as to whether he merits a place in Hodgson's side and, if so, in what position.
Rooney predominantly featured on the left for England and Welbeck, used on the opposite flank, feels the 28-year-old can help England move out of Group D.
"First and foremost, Wayne Rooney is a class player. Wherever he is playing on the pitch, he can make an impact," Welbeck said on Monday.
"All the England forwards have the flexibility to move around. Obviously Wayne was on the left in the first game, in the second or third game he could be in a different position.
"(Wayne) is the top all-time scorer for England currently playing - he's got 93 caps and he's very experienced, so when he's on that pitch he can make a difference."
With Raheem Sterling having seemingly secured the number 10 role immediately behind Sturridge, Rooney will likely be deployed on the left-hand side again for England's second game against Uruguay on Thursday.
Welbeck acknowledged the frustration that often goes with playing out of position but dismissed suggestions it would hamper the side as a whole.
"I think it could be quite frustrating for anyone playing out of position but that's football and you have to deal with it and it's not up to you who picks the team," he said.
"At the end of the day it's the manager's decision and you have got to respect that. You have to go into it and give 100 per cent, give it your best shot."
