The Real Madrid 33-year-old, who has been outstanding for Portugal thus far, missed training altogether on Monday. The 38-year-old Ricardo Carvalho is standing by in case Pepe cannot make it.
Wales – led by Pepe’s Real Madrid’s team-mate Gareth Bale – will be without the suspended Aaron Ramsey and Ben Davies. Andy King and James Collins are expected to step up.
He said: “Pepe is a fantastic player, he’s incredible for Madrid. He’s a very professional athlete and a great man. It’ll be a big loss for them so I’m sure he’ll do everything he can to get fit.
“We’ve lost Aaron and Ben and it’s horrible for them.
“The rules are difficult to take, you wish coming into the tournament that yellow cards and stuff would get wiped (by the semi-final stage).
“I’m sure deep down they’ll be hurt but they are doing everything to get behind the team. It’s given us even more motivation for us to win the semi-final and so they can play again.
“We are not doing it just for the nation and the badge now, we are doing it for them as well.”
Wales midfielder Joe Ledley has postponed his wedding due to his side’s prolonged stay.
The 29-year-old Crystal Palace man was due to marry on Saturday July 9 but has now rearranged it.