United went on to win the game comfortably although there were immediate concerns over the fitness of Rooney, who was voluntarily replaced by Park Ji-Sung after 76 minutes of the 4-0 victory at Old Trafford.
Despite the concerns, the former Everton ace, who, on Thursday evening, received the Football Writers' Association Player of the Year award, was quick to allay any fears that he wouldn't be fit in time for the World Cup.
"I'm fine. I went off on Sunday," Rooney told Sky Sports News.
"The game was won. My groin hadn't been right. For a few weeks it was tight. There was no need for me to continue in the game.
"I feel good now. I'm fine. I need to get a few more training sessions in before I play but that'll come when we meet up."
There is a great deal of weight on Rooney’s shoulders to perform for the Three Lions come June, but the pressure is nothing new for the striker, who has been dealing with media attention since the first time he took to the field for Everton as a teenager.
"I've been under pressure and in the spotlight since I made by debut with Everton when I was 16," he added.
"That's not really something that affects me. I know that if I do well then England have got a great chance of doing well.
"We've got a lot of match-winners in our team and some good players, so it's not just on me. It's on the rest of the team to do well for us."The United forward will undoubtedly carry the hopes of the entire nation in South Africa this summer but the 24-year-old is adamant that talk of expectations for himself and the Three Lions are for others to speculate on.
"There's a week's break now before we meet up with England and I am looking forward to the biggest tournament in the world and I cannot wait for that first game," he said.
"The expectation is for other people to talk about and think about.
"For me I am just looking to get myself right to get to the World Cup and do my best and with a bit of luck, hopefully we can be successful."
England boss Fabio Capello has already named his 30-man provisional squad in preparation for the finals and Rooney admits he is raring to go.
"I am looking forward to getting there with the lads and start the training for the game against Mexico and then it will be on to the World Cup," he added.
"We have got the players and the quality to do well and succeed at the World Cup.
"Hopefully we can stay injury-free from now on. If we can do that and all be at our best, then we definitely have the players to do well."
Speaking of his FWA award, Rooney explained he was delighted to receive the accolade and that it was all the more satisfying when you consider some of the past winners that have included the likes of Sir Bobby Charlton, George Best and Sir Stanley Matthews.
"It is a privilege to be given this award by the Football Writers' Association," said Rooney, who scored 26 Premier League goals this term.
"I am very proud. If you look at the list of previous winners, they are all great players and for me to be part of that now is a great feeling."
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