Robert Page has promised Wales will do everything possible to overturn the red card that looks set to rule Neco Williams out of their final Euro 2020 warm-up game.
Williams was left "devastated", according to interim manager Page, after being sent off in the 26th minute of Wales' 3-0 friendly defeat to France in Nice.
The Liverpool full-back was only a few yards away from Karim Benzema when he blocked the Real Madrid striker's close-range shot with both arms away from his body.
After a lengthy VAR check, Portuguese referee Luis Godinho considered it deliberate handball and brandished a red card to the bemused Williams.
Page said: "Neco is devastated in there. He wanted justification from the referee but he couldn't get it.
"We'll do everything we can to overturn it. If there is a chance to do it, we will.
"That's the disappointing thing. The plan was to play so many minutes today and building up to Saturday but we can't do that now.
"It was a harsh penalty anyway, to get him sent off as well a bitter blow.
"It changed the course of the game, for France as well I imagine."
Williams has had limited game-time at Liverpool this season, with the 20-year-old starting only three Premier League games for Jurgen Klopp's side.
Page had earmarked Williams for more minutes against Albania at the Cardiff City Stadium on Saturday.
But it now seems likely that he will have to sit out the final game before their Euro 2020 opener with Switzerland in Baku on June 12.
Wales winger Daniel James told Sky Sports: "I'm not one to talk about referees, but it's a friendly game.
"He took 10 minutes to look at it and then decided it's clear and obvious. I don't know how it's clear and obvious.
"He's two yards out and I'm not even sure it's a penalty.
"We've been told that if he's in a natural position and he can't do anything about it's not a penalty. Even their players were saying 'don't send him off'.
"If it had happened against Switzerland we would be a lot more gutted."
Wales had started brightly against the world champions and James forced a fine fifth-minute save from France captain Hugo Lloris.
But France made their extra man count with ruthless efficiency as Kylian Mbappe, Antoine Griezmann and Ousmane Dembele scored in what was eventually a comfortable victory.