Carrick marked 11 years at the club with a match to benefit his charitable foundation in front of 70,027 fans and while the midfielder will be around for another 12 months after signing a contract extension, fans may have witnessed Rooney's final appearance in a Red Devils shirt.
He played the entire first half and the final 17 minutes of the second and in that time the club's all-time leading goalscorer, who has fallen out of favour with manager Jose Mourinho and appears destined to leave this summer, lobbed one early effort onto the roof of the net.
While Rooney could be excused to some degree, having flown back from a family holiday in Barbados to play in the friendly, it was perhaps indicative of his current situation that he did not particularly stand out in the company of a host of long-retired ex-professionals.
At the final whistle he gave a quick wave to fans before heading down the tunnel.
Carrick, who saw a deft first-half chip drift wide of the angle of crossbar and post, scored the equaliser in a 2-2 draw eight minutes from time before departing to a standing ovation.
Despite more than a decade at United the pre-match team sheet somehow managed to spell the main man's name wrong – he was originally listed as Carrtick before the error was quickly corrected.
The midfielder offered his condolences to the victims of both Saturday's London attacks and those in Manchester a fortnight ago.
Kick-off for the game was brought forward so as not to clash with the One Love Manchester concert being held at the neighbouring cricket ground later in the evening, in aid of the those affected by the suicide bomb attack at the Manchester Arena on May 22 which killed 23 people.
A number of victims' families were in the Old Trafford crowd, as were about 300 members of the emergency services who dealt with the aftermath of the atrocity.
"Obviously this game has extra significance in the wake of what has happened in the last two weeks," said Carrick, who laid floral tributes ahead of a minute's silence for victims of both attacks.
"I'd like to extend my condolences to those affected by the events in Manchester and also those in London.
"My heart goes out to all those affected and my message is stay together and stay strong.
"On my behalf I'd like to welcome some of the families of the victims.
"I'd also like to welcome about 300 of the emergency services who were heroic in their efforts in the last couple of weeks."
Regarding the testimonial itself he added: "The atmosphere was incredible. There was no way I could have hoped for anything like this.
"I know we get full houses here every week but it is not something I take for granted and to get so many here is sensational.
"I have to thank the fans for their support. Let's not forget we're back here next season to try to win some more trophies..
"And finally a thank you to Sir Alex (Ferguson), the man who brought me to the club.
"We all know how great he is and his achievements at the club but he's been a massive influence on my career. Thanks very much boss."
Former Lazio, Barcelona and Middlesbrough midfielder Gaizka Mendieta's 22nd-minute strike was cancelled out by Nemanja Vidic's header for the Manchester United '08 XI just before the half-hour.
Midway through the second half, Robbie Keane put the All-Stars XI ahead only for Carrick to fittingly have the final word.