Van Persie is on the brink of completing his big-money move to Old Trafford after Arsenal reluctantly allowed him to leave. Providing the 29-year-old is registered before Saturday's noon deadline, he will go into Sir Alex Ferguson's squad for the Premier League opener at Everton on Monday.
And 21-year-old Welbeck believes it is a positive move by Sir Alex Ferguson, as he said: "He's a world-class striker. He can score goals and create them as well. They are the type of players who do win you titles. It's given the club a massive boost."
He added: "Everyone is delighted to have him and I'm really looking forward to playing with him."
Indeed rather than be put off by the competition, Welbeck welcomes it, believing it will push him on to the next level.
"It's always good to have competition," he said. "You never sit back. But at United there's no time to sit back anyway. You always want to win every single game. It's going to be a good challenge to have.
"In any case, once the season gets under way the manager will be good with squad rotation. It's a good problem for him to have. He's got a good variety of strikers to use and hopefully he picks the right team and we can win as many titles as possible."
With Javier Hernandez and Wayne Rooney already at the club, Ferguson has already mentioned the likeness to his 1999 treble-winning quartet of frontmen.
As a United fan, Welbeck remembers the deeds of Dwight Yorke, Andy Cole, Teddy Sheringham and Ole Gunnar Solskjaer so well. And after missing out on the title by the narrowest of margins last term, now he can only hope to enjoy the same kind of success.
"United are always going to be serious about winning Premier Leagues and that won't change," Welbeck said. "I'm sure there were plenty of other teams after him as well as City, that maybe couldn't have got him. But hopefully United will sign him and that's the main thing."