Rooney's future has been the subject of intense speculation over the last few weeks, with the Manchester United striker said to be determined to leave Old Trafford.
United had rejected two bids from Chelsea for Rooney, who has been sidelined with what the club say is a shoulder injury.
Even though Rooney has not made a full appearance in pre-season for the Red Devils, he was so desperate to show that he was fit yesterday that he started training half an hour before the rest of his team-mates.
Gerrard says Rooney has been in excellent form in training over the last 48 hours and he expects the 27-year-old to cast aside his problems when he lines up for the Three Lions against Scotland on Wednesday night.
He said: "Sometimes players have huge decisions to make and the spotlight is on those individuals, but I think once the game has started, you have to park whatever is going on off the pitch.
"You have to concentrate on doing the best job you can for the country, and that does happen once the whistle goes.
"Everyone knows Wayne is not match fit because he hasn't played any friendlies, but he looks fit, he looks good in training and is scoring goals. He is certainly ready to play, he needs these minutes to get fit and I am sure he is itching to start tomorrow."
Even though Gerrard and Rooney play for two of the biggest rival clubs in the country, the pair are close.
Rooney was a guest at the England captain's wedding in 2007, and the pair have shared many experiences while on international duty together.
Gerrard revealed today that Rooney had sought his advice on his future, but the Liverpool midfielder refused to reveal what was said between the two.
"Yes, we have (spoken)," Gerrard said. "But it wouldn't be fair on Wayne to talk about what we have talked about."
Gerrard did admit, however, that England would be at a big disadvantage for their two upcoming qualifiers against Moldova and Ukraine next month if Rooney was not playing regularly by then.
"That is a scenario we will have to wait and see what happens," the 33-year-old said.
"But it's important to have him fit, of course. He has shown over the years how important he is.
"He has been the key to getting us to major tournaments, he is one of our best players so it's important that he gets fit as soon as possible and we need him firing over these four qualifiers."
Rooney, of course, has not been the only player close to Gerrard whose future has been up in the air this summer.
Luis Suarez and Liverpool are at loggerheads over his future, too. The Uruguayan wants Champions League football, but Gerrard has not given up hope of hanging on to the striker.
"It's very important he stays," Gerrard said.
"He is one of the best players in the world. I can understand why clubs are showing an interest in him.
"If I can use my influence to try to get him to stay then of course I will because I love playing with him and I don't want him to go and for Liverpool to be successful and move forward we have to keep our best players."
Arsenal have launched a bid of over £40million for Suarez, but Gerrard thinks Liverpool will not sell the star to a rival club.
"At the moment I haven't got a clue (if he will stay) or not," Gerrard said.
"But I am really confident he won't go to anywhere else in England."