SIMON GRAYSON has admitted his frustration at Jonny Williams’ ongoing fitness issues, with the Welsh midfielder struggling to be available for tomorrow’s trip to Brentford.

Williams has arguably been Sunderland’s most polished midfielder since joining on loan from Crystal Palace on August transfer-deadline day, but a variety of ailments have restricted him to just three starts.

A bout of serious migraines limited his ability to train at the end of last month, and while he was able to play in Wales’ World Cup qualifying defeat to the Republic of Ireland, he was short of fitness when he returned from international duty and was only able to appear off the bench in last weekend’s 1-1 draw with QPR.

He produced an eye-catching second-half cameo six days ago, but his efforts came at a price as he sustained a hamstring injury that has prevented him from training this week. As a result, he is a major doubt for tomorrow’s game at Griffin Park.

“It’s probably been the story of his career so far,” said Grayson. “It’s been stop-start. I think somebody said to me that he’s played 50 games in three years – he would like to have played a lot more.

“I know he dislocated his shoulder at Ipswich (during a loan spell), but he just keeps getting a niggle here and there. That doesn’t help with my team selection because I want to play my most talented players, and players that I’ve brought to this club to affect the game.

“Jonny showed last week what a good player he is. Could I have started him for that game? Not really, because I felt that he wasn’t in the right physical condition. That showed after the game when we found out he’d picked up a slight hamstring strain.

“When I make decisions for the team, it’s done with the best interests of individuals and the team at heart. It’s not because I want to put square pegs in round holes. I do it because I think I’m picking the right team for that game.”

While Lee Cattermole and Didier Ndong tend to patrol the area in front of the Sunderland back four, Williams is one of the few central midfielders at Grayson’s disposal who looks to get on to the front foot.

With Duncan Watmore now available to partner Lewis Grabban in attack, and Aiden McGeady, Callum McManaman and George Honeyman vying for the wide positions, Williams could be the player that knits the Sunderland midfielder together.

However, he will not be able to play that role while he is sitting on the treatment table, with Grayson growing increasingly frustrated by his absence.

“I watched the QPR game again on Monday, and Jonny was the one that really made us tick,” said the Sunderland boss. “He went looking for the ball, even from (Jason) Steele’s goal kicks where other players didn’t have that bravery.

“He wanted to take responsibility to get on the ball and make things happen. That’s the type of player that he is, and when we have him available, he’s a key player for us.”

While Williams has impressed in his handful of appearances in a Sunderland shirt, his fellow midfielder, Cattermole, has been below his best for much of the season.

Despite having played the whole of his career in the top-flight, Cattermole has struggled to dominate games since his drop down to the Championship, but Grayson claims he is hardly alone in that failing.

Far too many Sunderland players have been underperforming this season, and while Cattermole might be one of the more high-profile offenders, it would be unfair to be too critical of his performances when his commitment has not wavered.

“I think Lee is like a lot of the players, they’ve probably not played to the best of their capabilities,” said Grayson. “If all our players were playing to the best of their ability, we would be winning matches. Because the majority are not playing to that level, it’s making it difficult to win.

“I think Lee falls into a category of a few other players in that respect. But what you know you’re going to get from Lee Cattermole is hunger, desire, commitment and some real leadership qualities as well. We know his injury record over the last year or so has been difficult, but so far he has been fit for nearly every session and fit for every game.”

Lamine Kone has been passed fit for tomorrow’s game after recovering from the illness that laid him low last weekend, but Tyias Browning remains a doubt despite having returned to training yesterday.

“Lamine trained on Monday morning,” said Grayson. “He was ill overnight (last) Thursday and on the Saturday was still not able to play. Tyias has trained now, so we’ll see where he is (later today). Marc Wilson was back on the grass (yesterday), although I think Saturday will probably be too soon for him.

“Paddy (McNair), Josh (Maja) and Joel (Asoro) will play for the Under-23s at Everton (tonight) and probably get 60 or 70 minutes. They played well the other night, and they’re making progress towards selection for the first team.”