"When we had the announcement for the Rugby World Cup squad on Monday, there were a few guys (with injuries)," explained the Corkman.
"Brian (O'Driscoll), everyone knew that he had taken a knock on the shoulder and it was a little bit sore.
"Sean was another one that I had said had taken a bit of a bang in the match against France on Saturday. He picked up the injury after about 50 or 55 minutes.
"He has a bit of a tear on one of the ligaments, but as you can see he was out training already this morning on the pitch.
"It's not like he is laid up in bed or anything like that. It just goes with the territory unfortunately in sport. He's up and going again.
"He's not available for this one (against England) and then we don't have another game for another two weeks. We would be hopeful that he will be available for the American match."
Stephen Ferris and Keith Earls will deputise in the duo's absence this weekend. Ferris will make his first start since last year's GUINNESS Series, while Earls gets a chance to partner Gordon D'Arcy in the centre from the first whistle.
The pair lined out together in the closing minutes of the home win over Argentina last November, with Earls having come on in place of O'Driscoll.
Expanding on O'Driscoll's injury Kidney added: "Brian picked up a knock last week. As you can see he is running around outside (in training), flying, but it was prudent to us not to put him into a contact situation this week.
"He has made good progress especially over the last 24 hours. With the game coming this week and a full tournament coming up, it just wasn't prudent to put him in the mix.
"I don't have the actual medical term for it. He gets stingers around this area (shoulder). Sometimes you just need to rest it up and get them out of the system."
Full-back Rob Kearney was due to come in and win his 30th Ireland cap against England. However, he is ruled out again having missed the France game with a groin strain.
Geordan Murphy will don the number 15 jersey for the Aviva Stadium send-off, slotting in for his first start since the aforementioned victory over Argentina.
"Rob pulled up. He was training fully on Monday and Tuesday, and just pulled up a little bit sore on Tuesday," said Kidney.
"We just checked it out. It's just better to ease up on him for a couple of days. He will be fine again after this weekend.
"With Geordan coming back into it, where we are now it's an opportunity to give him a start in another game.
"At this stage it is all about looking at the part of the glass that is full in terms of giving lads game-time. It will be good for Geordan even though it will be disappointing for Rob not to be considered."