Centre-back Williams joined up with the Wales under 21 squad for this afternoon's UEFA Bosnia-Herzegovina match immediately after Wrexham's 2-0 defeat at Brentford on Saturday.

That meant the 21-year-old missed Monday's goal-less draw against Dagenham and Redbridge at The Racecourse, a result which leaves the Reds seven points away from safety.

Although unhappy to have sat out The Daggers' clash, Williams turned his attention to helping Wales qualify for the championship play-offs today in Bosnia where he was expected to continue at the heart of defence.

Group 10 leaders Wales have to win two of their final three matches to reach the play-offs. They complete their group campaign with a double header against Romania later in the year.

"I am looking forward to the Wales game but it is tinged with disappointment at losing against Brentford and missing Monday's match," said Williams.

"I have played every minute of every qualifier for Wales. We have done well so I was debating trying to play on Monday and then maybe meet up with the squad afterwards but I couldn't. I am gutted I had to miss the game and let Wrexham down.

"But it is an important qualifier with Wales, we are going well and I want to get through to the play-offs. I want to see it through to the end.

"If we get a good result against Bosnia, we are in a good position going into the last two qualifiers where we can push on for the play-offs. We would just need to win one of our last two games then to qualify.

"But we have been on a good run and we are looking to win all three games. That is the way we have gone into every game."

Wales are boosted with the inclusion of Totteham Hotspur defender Chris Gunter who is in Brian Flynn's squad rather than linking up with the senior side for the friendly in Luxemburg.

Wales beat Bosnia 4-0 at The Racecourse last November earlier in the campaign but Williams knows a win is not a formality.

"We have got are a few players coming in," said Williams. "The likes of Gunter brings experience so we are going out there positive.

"It was a comfortable win at home but it is always different when you go away to these places. But hopefully I will be coming back on Friday and we will have three more points on the board, and I can look to Wrexham."

Prior to missing Monday's draw against Dagenham, Williams had enjoyed an extended run in the Wrexham side. He had started eight of Wrexham's previous nine matches, and he switched to a left back position from the centre of defence at Brentford because of injury to Neil Taylor and Carl Tremarco.

But Williams knows he faces a battle to re-claim his place for Saturday's vital League Two clash against Barnet at Underhill.

"Hopefully whoever comes in does the job and it might be a case when I come back, I might have to push to try and get back into the team," said Williams.

"Since I have got back into the team we have done alright and picked up some points, though everyone was disappointed to lose at Brentford.

"I feel I have done okay and the gaffer must think so because he has kept me in the team, either playing left-back like I did on Saturday because of the injuries or centre-back.

"But if you ask any player, they don't mind wherever they play as long as they are on the pitch."

Hopes of avoiding relegation were dented after drawing against Dagenham, with fellow strugglers Macclesfield beating Barnet and Notts County drawing at Shrewsbury.

With games in hand on all their relegation rivals, Williams knows the games will be coming thick and fast during the run-in.

"It is a big end to the season for us, a massive six weeks," added Williams. "There are a lot of games and we will be playing Saturdays and Tuesdays every week I think.

"We will see if I am in the team on Saturday but if I am not, I will have to wait for my chance again.

"Basically the lads are all part of this together, whoever is playing. We just want to try and get out of the position we are in, and every game is huge."