CELTIC boss Ronny Deila admitted he blundered by starting Stuart Armstrong in the 2-0 win over Partick Thistle yesterday.
The midfielder lasted only 20 minutes before going off with a groin injury with Callum McGregor taking his place.
And Deila is unlikely to risk Armstrong or skipper Scott Brown in the game against Kilmarnock at Rugby Park on Wednesday night.
The Hoops gaffer revealed: “Stuart was stiff and tight in the groin before the game. We should maybe have rested him, but I wanted to play him and that was a bad decision.
“However, it is nothing serious. If you are only 90 per cent fit, you should not be on the pitch.”
Deila is also confident Brown’s absence will be short-term. He added: “Scott has played every second of every match before Firhill and has done a lot of running in the past few weeks.
“He was stiff in his hamstring and had a small cramp at the end of the Qarabag game. So he needed to miss the Partick Thistle game and maybe the next one.
“We will see what we do with him. After that, he will be very ready again.”
