"He's a world-class striker who can not only score goals, but lay on assists," Young told the club's official magazine, Inside United.
"Robin's also great from set-pieces. He's an all-round player and exactly the type a club like United should have - we want the best players.
"He's fitted in very well but it's easy for any player that joins United to fit in because the players here are so good at making you feel welcome and really help you settle in.
"It's still only early days, but you can already see he's formed some good link-ups in training and on the pitch. He's a great addition to the squad and I'm sure he will have a big impact this season."