Leicester boss Brendan Rodgers insists Caglar Soyuncu was not rushed back after the defender suffered a recurrence of his recent groin injury against Zorya Luhansk.
Soyuncu was forced off just 16 minutes into his return during the Europa League group game in Ukraine following a six-week absence.
The Turkey international came across to the right to deal with a through ball and immediately pulled up, kicking the ball out to receive attention.
He signalled to the bench – his hip area appearing to be the problem – and hobbled off, with Wesley Fofana coming on in his place.
Soyuncu will now undergo tests to determine the severity of the problem, but Rodgers denied it was a case of bringing him back too soon.
"It's just in around his groin," said the Foxes manager. "It was the moment for him to come in. He went through all the protocols with the medical team and was fine.
"He's been training for quite a long period. This was a chance to put him in. He was motivated and ready to play.
"But it looks like he overstretched his groin a touch and he felt a twinge, so we'll need to analyse that when we get back on Friday."
Rodgers felt defeat was harsh on his much-changed side after the Foxes lost their unbeaten record in the Europa League.
Substitute Allahyar Sayyadmanesh scored six minutes from time to inflict a first defeat on Leicester in the competition. They remain top of Group G thanks to their head-to-head record against Braga and will finish first if they win at AEK Athens in their final group game.
"I thought we were very unfortunate to lose the game," said Rodgers, who made nine changes from the Premier League defeat to Fulham on Monday.
"We had a lot of good moments and their goalkeeper made some good saves. I'm so disappointed for the players because they put so much into it. They didn't deserve to lose.
"There were some real moments of quality and as the game wore on I thought we looked like we would score.
"But congratulations to Zorya. There was more on it for us and we wanted to win and I thought we showed a great desire to do that."
Apart from the setback with Soyuncu, Ricardo Pereira and Wilfred Ndidi also made their first starts after recovering from injury, playing 45 and 56 minutes respectively.
Rodgers said: "We are pleased. We had players coming back from injury so that was a positive for us. We knew what tonight was in terms of getting game time into the legs of players who needed it."