Cooney yesterday underwent surgery on a hamstring injury which will keep him out of action until April at least in the latest setback to hit the Tipperary native.
Cooney, who played 22 times for Connacht last season, had been troubled by an ankle injury earlier this season and was working his way back into action in the B&I Cup and with Garryowen.
The 27-year old has not played for Connacht since his 50th appearance for the province against Munster last May.
Most of Cooney’s appearances for Connacht since he joined five seasons ago have been off the bench — he was an unused replacement in the PRO12 final win over Leinster in 2016.
“JP unfortunately has a really serious injury now,” said coach Keane.
“That will take him out for the season. He has been a great squad member, very humorous man and keeps everybody on their toes with that humour. We will miss him around the changing rooms but we wish him well.”
Keane is hopeful that loosehead Buckley might yet be available for the visit of Ulster on Saturday, with the 27-year-old due to see a specialist about an ankle injury picked up in the 55-10 Challenge Cup win over Brive at the weekend.
“Not at this stage, no,” said Keane, when asked if Buckley had been ruled out of the Ulster game on Saturday. “Denis is getting a scan and we won’t know the outcome of that until later on.”
And Keane is also hoping that Jarrad Butler, perhaps Connacht’s player of the year before undergoing knee surgery at the end of October, might also be back for the start of the three derby clashes.
Butler, who joined during the summer from the Brumbies, is being integrated into training this week and Keane has not ruled him out of featuring against Ulster.
“We are confident, he is doing really well. We will make a call on that probably this evening. I am feeling positive about Jarrad,” added Keane.
His side go into the festive derbies on the back of impressive wins over Brive which leaves them in a great position to nail down a home quarter-final in the Challenge Cup.
And with Connacht away to Leinster and Munster over the festive period, Keane knows that a good result at home to Ulster on Saturday evening at a packed Sportsground — extra terracing is being introduced for the game — will give them momentum.
“It’s similar to the first round of the Challenge Cup where we used that to give us a bit of momentum. It’s brought a lot of bounce around the place, a few smiles and a bit of humour which is good,” added Keane.