The England international brought up the milestone as he netted twice in the 4-2 Champions League win over Bayer Leverkusen to move into fourth-place on the list of the Red Devils' all-time top-scorers.
Rooney has had a tumultuous summer with Chelsea seeing two bids turned down to acquire his services while speculation also mounted surrounding a potential move abroad.
But the 27-year-old looked more than settled on Tuesday as United manager David Moyes won his first Champions League game at Old Trafford and Carrick was delighted to see the striker back to his best.
"It was probably Wayne's best performance that I've seen for a while," the midfielder told www.manutd.com.
"It's great to have him in that form - he can be untouchable when he's like that."
Rooney reached the landmark in just 406 games and now sits behind only Bobby Charlton, Denis Law and Jack Rowley in the club's list of top marksmen.
The achievement has brought the former Everton man many plaudits and former defender Viv Anderson, who made 69 appearances for United, believes he deserves to be regarded as one of the club's greats.
"He's a United great and his record says that, 200 goals is great," he told Press Association Sport at an event in Rotherham to promote Vauxhall's Youth Football Programme for which he is an ambassador.
"He is only 40-odd short of Bobby Charlton and Denis Law, so he has to be talked about like that.