Ireland wing Simon Zebo will miss the remainder of the RBS 6 Nations after breaking a bone in his foot in Sunday's 12-6 defeat by England at the Aviva Stadium.
Zebo underwent an operation on Monday to repair the damage incurred in the 10th minute of a brutal Test in Dublin and has been ruled out for up to 10 weeks.
Flanker Sean O'Brien (tight hamstring), lock Mike McCarthy (knee ligament strain), centre Brian O'Driscoll (twisted ankle) and lock Donnacha Ryan (back) also sustained injuries, but have yet to be ruled out against Scotland in two weeks' time.
"Simon will have surgery while. Jonny will have a scan,"said Kidney.
"It looks like a couple of weeks for Jonny, but it would be wrong to try and second guess the outcome. We'll know more by Tuesday.
"It's been an attritional couple of games and we had a few injuries leading into the tournament, but that's the way it goes."
Four penalties by Owen Farrell underpinned England's first win in Dublin since 2003 and ensured Stuart Lancaster's team now stand alone in the quest for a Grand Slam.
Ireland controlled long spells of the match but were hamstrung by some dismal handling that was poor even when the slippery conditions were taken into account.
England, who were calm and composed despite the ferocity of the encounter, were less afflicted and captain Jamie Heaslip sought alternative reasons to explain a frustrating defeat.
"I don't want to blame the conditions because both teams played in them," Heaslip said.
"There were a lot of knock-ons and unforced errors. I don't know what caused all the errors.
"It was frustrating and we constantly tried to regroup and go again. England played a good pressure game.
"There were a lot of sore guys in the changing room, particularly because of the hits they took but also because they lost in a green jersey at home."
Ireland will remain in title contention if England lose one of their remaining three games and Kidney refused to concede his team's dream of winning the championship is over.
"This gives England a bit of daylight with the other five sides on two points each with three matches to play," Kidney said.
"We're extremely disappointed because that wasn't the result we wanted. Let's see what France come up with at Twickenham. England have to go to Cardiff too.
"There's still a hell of a lot to play for. What we have now are three more opportunities to get three wins. Let's get to eight points and see where we are at the end of it.
"The Grand Slam is a wonderful thing to win, but first and foremost you play for the championship and we're still well in for that," he added.