Carrick, on the losing side as United lost the Community Shield on penalties against Chelsea yesterday, is expected to form a midfield axis with Darren Fletcher this term as Sir Alex Ferguson reshapes his squad in the absence of Ronaldo, an £80m departure to Real Madrid.
The England midfielder has won a major trophy in each of his three seasons at Old Trafford since his £18.6m arrival from Spurs in August 2006.
But despite claiming his third Premier League winners' medal last May, the 28-year-old admits that losing to Barcelona in Rome has ultimately been the defining memory from last season.
Carrick said: "I tried to switch off and relax during the summer, but it was quite hard after what happened in Rome. I'm still trying to get over losing the [Champions League] final, and I don't think I will until I win it again.
"But when you look at the bigger picture, it was a successful campaign. We went to Japan and came back as world champions, won the Carling Cup and went on to win the league for a third time in a row, so we showed how good a team we are.
"Losing like we did in Rome was hard to take, though, and no-one wants to experience that again. It's certainly the worst I've ever felt after a match. It took about a week for any of my family to be able to talk to me properly.
"We've all learnt a lot from what happened and are determined to come back stronger this season. It's the same as always. We're ready to go again.
"That's the beauty of this club, despite all the success, every year you come back and want to achieve more. What's happened has gone, now it's about looking forward and trying to earn it all over again."
United begin the defence of their title at home to promoted Birmingham City on Sunday with the team still taking shape following the exit of Ronaldo.
But Carrick is confident that United, following the additions of Michael Owen and Antonio Valencia, have the quality to become the first English club to win four successive league titles.
He said: "I don't think it (the squad) can be questioned. The gaffer has assembled a fantastic group, bringing in a great mixture of younger lads and experienced players, and the strength and depth here is second to none.
"Obviously losing Cristiano was disappointing because he's been a huge player for us, but we've got a lot of top players here to deal with that and still be successful."