Wales reached the last four of a major tournament for the first time in their history by beating Belgium 3-1 and will now meet Ronaldo's Portugal in Lyon on Wednesday for a place in the Paris final on July 10.

But they must do so without influential playmaker Aaron Ramsey and key defender Ben Davies, who has been part of an impressive three-man Wales central defence alongside Chester and skipper Ashley Williams.

"They've started every game for us so far and will obviously be a big miss," Chester said of the suspended pair, who picked up their second bookings of the tournament against Belgium.

"Aaron has undoubted ability but how much work he puts in maybe gets overlooked.

"Ben has been our stand-out defender in the tournament so far, but the big thing we've got in this squad now is strength in depth.

"We have players to come in who have played at the top level, so hopefully it won't hamper us too much."

West Ham defender James Collins is likely to deputise for Davies in Lyon. Collins came on for the few final seconds against Belgium in Lille, his first action of the competition.

"All the lads who haven't played have been great," said Chester.

"I know myself how difficult it is to be watching every week, but their attitude has been great. They've looked after themselves well and whoever comes in will do a good job."

Portugal have reached the semi-final without winning once in 90 minutes in France. They drew all three group games against Iceland, Austria and Hungary before knocking out Croatia in the last-16 with a late extra-time winner.

Portugal progressed further by beating Poland in a quarter-final penalty shoot-out, but they have not really impressed and Ronaldo has yet to light up the tournament, despite scoring twice in the 3-3 draw with Hungary.

Chester, however, admits the Real Madrid forward was a player he looked up to in their time together at Old Trafford and says that he had a profound impact on his career.

"He was at United when I was a young lad and I just remember what I took from him, how good a professional he was, how he looked after himself," said Chester.

"It's something I've taken through my career and it's took me as far as I've got. Just watching him really - I'm well aware of how fortunate I am to have come through that club at that time. To watch players like him and see how they behave has been massive for me throughout my career."

Wales will start as underdogs again on Wednesday but Chester said: "I don't see any reason why we can't [beat them].

"They've had to go to extra time twice, that's of benefit to us. If we play like we did against Belgium, and like we did against Russia, we'll be a match for anyone."