BOSS Brendan Rodgers has described Ashley Williams as "invaluable" as the defender prepares for a return to the club who told him he was not good enough.

It was just over a decade ago that West Bromwich Albion released the teenage Williams because they felt he would not make the grade at the Hawthorns.

He goes back to his native Midlands to face the Albion tomorrow as one of the most consistent centre-backs in the land.

It is hard to believe now that Williams was cast adrift by the Baggies, whose rejection forced the youngster to drop down into part-time football with Hednesford Town.

"There are times in your career that you will probably look at as defining moments," Rodgers says.

"I was told I was not good enough as a manager by Reading, a bit like Ash was told he would not make it as a player.

"But when those moments come, you ask yourself 'Am I a failure, or is this a defining moment?'.

"Ash has shown he has that character to battle back, and that West Brom just wasn't the right time for him."

Brought to Wales by Roberto Martinez in 2008, Williams has proved to be one of the great Swansea signings of modern times.

Having done his time at Hednesford, the Tamworth-born star progressed to Stockport and then on to the Liberty in a deal which eventually cost Swansea a mere £500,000.

He had to be patient initially, as Martinez kept faith with the players who had carried Swansea towards the League One title at the back-end of the 2007-08 season.

But when Swansea's Championship adventure began at Charlton Athletic the following August, Williams had claimed a place in the side.

Incredibly, Williams has not missed a league game since.

Rodgers suggests that "five or six" members of his Swansea side could play for any club in the Premier League and not look out of the place.

It goes without saying that Williams is one of them.

"Absolutely no question," he nods.

"Ash is a top, top player and he is invaluable to me.

"I look at some of the players moving around for £5 million or £7 million or £10 million and I don't know what price I would put on him."

Rodgers shies away from suggesting Williams is unsellable, for Swansea are not Manchester City.

It is safe to say, however, that it would take an offer of extraordinary proportions to persuade Swansea to do business.

"This is a guy who can play football as well as defend," Rodgers adds.

"I know a lot of clubs looked at him earlier in his career and felt he maybe wasn't big enough or tall enough to play as a centre-half at the top level, but I'm not sure I would swap him for many,'' he went on.

"He was man of the match against Spurs, man of the match against Arsenal, man of the match against Chelsea, but he does not just produce in the blue-chip games.

"He is a player who performs every time he goes out on to the field."

At 27, Williams should only just be coming into his prime.

And Rodgers believes there is more to come from a player who, in his eyes, does not have a weakness.

"I know when I first came to Swansea people were looking and saying Ash was not big enough.

"But for me it's not an issue.

''Ash is around 6ft, but he has shown he can outjump players who are 6ft 4in or 6ft 5in.

"He is as quick as any defender on the turn and mentally he is very tough.

"He is a top defender, but when he has possession of the ball he does not just get rid of it, he looks to play."

Williams has courage, too, for that is a fundamental requirement for any centre-back in a Rodgers side.

Back on familiar territory this weekend, Williams will lead out Swansea as they attempt to pass their way to a second league away win of the campaign.

The 31-cap Welsh international should have his chest puffed out as he steps out at his former club — and so too should those behind him.

Swansea were pegged in stoppage time against Chelsea in midweek, but their performance in the draw was another major confidence boost.

Rodgers's team look more at home in the Premier League with every game that passes just now.

"I always felt that we would be stronger in the second of half of this season because of the confidence and belief we would gain," Rodgers says.

"And what gives me belief that we will continue to get results is that we have players who, just like me as manager, are very hungry to stay at this level.

"We have all worked ever so hard through our careers to arrive at this level and, now that we're here, we want it to continue."

So successful have Swansea been on their own patch this season that it could be argued that they will gain enough points to avoid an immediate return to the Championship via home games alone.

But there is a determination within the Swansea squad to ensure that is not the case.

They want more travelling success after the maiden road win at Aston Villa a month ago, and a trip to West Brom — owners of a miserable home record — represents an opportunity if they can perform.

"Roy (Hodgson) is a wonderful coach who sets his teams up very well," Rodgers says.

"They play a certain way and are very patient, and that means we may have to be very patient this weekend.

"But I think if there's a team who have that patience in possession, it would be ourselves.

"It will be a difficult game for us, but it is one we look forward to."