Neil Taylor was "despondent" after his horror tackle on Seamus Coleman left the Everton defender with a broken leg.
The incident occurred 21 minutes from the end of Wales' 0-0 World Cup qualifying draw against the Republic of Ireland on Friday.
Taylor launched into a challenge and caught Coleman's right leg, causing a sickening injury and earning the Wales man a straight red card.
Visiting boss Chris Coleman defended the character of his full-back and offered his best wishes to his injured namesake.
"First and foremost, the most important thing is Seamus Coleman," he told Sky Sports. "We are told that it is not so good, which we are sorry for.
"Neil Taylor is not really that type of player, but it's a tough one for Seamus. Our thoughts are with him. I have not seen it again.
"Neil is in the dressing room, he's despondent. If he's got it wrong...he's had a serious injury himself.
"I have my fingers crossed for Seamus Coleman, he is the most important thing tonight."
Wales talisman Gareth Bale picked up a yellow card that rules him out of the trip to Belgrade in June, with the Euro 2016 semi-finalists four points behind Ireland and Group D leaders Serbia.