Worried Shaun Maloney says Kevin Nisbet's injury "doesn't look good" after the striker went off against Celtic.
And the Hibs boss appeared furious with Carl Starfelt's challenge that left Nisbet in agony.
It was a cagey clash at Easter Road as Hibs held on for a point against the Premiership leaders but celebrations were overshadowed slightly by a first-half blow to Nisbet.
Starfelt was booked for scything down the striker as he broke away on the counter and Christian Doidge was called upon to replace him.
A ruffled Maloney told Sky Sports after the game. "It doesn't look good.
"It wasn't a good challenge, I understand that they try and stop counter-attacks very quickly like they did in the first game, but this particular challenge looked like a bad one."
However he was asked if it was a season-ender and he stopped short of confirming that, adding: "No, we've only seen it the last couple of hours so I hope it's not too bad. But at the moment it doesn't look too positive."
But Maloney was delighted with his team's overall performance as he went on: "We defended extremely well. I'm very proud of the team.
"In the first half we played more, in the second we had to defend for long periods.
"They had the character and mentality to try as hard as they could and never give up throughout the 90 minutes, to not give up easy opportunities. It was a big test for a very young team.
"Towards the end they gave us almost everything and that meant we got deeper and deeper.
"We had a slight counter-attacking threat but maybe not as much as we'd hoped. But I can't criticise my players today, we were fantastic."
