Liverpool boss Jurgen Klopp says he needed to stay strong and put a stop Jordan Henderson's efforts to play in the second half after planning to substitute him at half-time against Midtjylland.
Klopp made four changes to the side which beat Sheffield United on Saturday but captain Henderson kept his place in the starting line-up.
In the first half, Liverpool lost Fabinho to a muscle injury and it disrupted their momentum as they were held to 0-0 at half-time.
After the break, Henderson did not return to the pitch, having been replaced by Georginio Wijnaldum, which led to claims he may also have picked up a knock.
Diogo Jota and Mohamed Salah scored in the second half to hand Liverpool all three points and keep them on top of Group D.
In his post-match press conference, Klopp confirmed he would know more about Fabinho's issue on Wednesday morning and explained his reasons for taking off Henderson.
“First, Hendo said at half-time he wants to play on," Klopp said.
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"Before the game, I’d decided already we have to share it - 45 and 45 – and all the rest would have been ridiculous.
“Hendo said at half-time, ‘No, boss, I can go on’ and then in these moments, you have to be strong to yourself because I didn’t want to lose him, actually.
“We made the change, Gini did really well and for both I think it helped that they played only 45.”