Winston Reid is now "close to the top echelon of defenders" in the English Premier League, according to one of the BBC's top football analysts.
Former England and Tottenham midfielder Jermaine Jenas says Reid is getting better with age and, if he maintains his consistency, will be a definite target for a "top four club".
Reid, who played for West Ham against Crystal Palace overnight, is in his sixth Premier League season. Injuries have restricted his appearances this campaign but the 27-year-old All Whites captain has still been a key element of West Ham's best season in decades.
"Winston has matured vastly," Jenas told the Herald on Sunday. "He's always been athletically strong and quick but, at centre half, you need to have a good understanding and reading of the game and that is what we've seen in Winston. That's what has attracted quite a few teams to try to poach him at times."
Jenas played 277 Premier League games, mainly for Newcastle and Spurs. He also earned 21 England caps and played under influential managers such as Sir Bobby Robson, Graeme Souness, Sven Goran Eriksson, Fabio Capello and Harry Redknapp.
Since his injury-enforced retirement in 2014, Jenas has become the youngest regular pundit on the BBC's Match of the Day programme.
The 33-year-old, who faced Reid on the field several times, has been surprised at his progress.
"From when he first came over to now, I am surprised in his development and how good he is," said Jenas. "It sounds a bit rude to say that but, when he first started, he was a bit raw."
Reid struggled to adapt to the pace and unforgiving nature of the league in his first season at West Ham, before getting a chance to find his feet in the Championship in 2011-12.
"Early on, there were more mistakes in his game," said Jenas. "Now he is fully concentrated for the whole game. You don't see as many mistakes any more, which reassures the whole team. He is now close to the top echelon of defenders in the Premier League."
Reid could become a wanted man. He signed a six-year contract extension in March 2015, ending months of speculation about his future amid reported interest from Tottenham and Arsenal.
"West Ham have done well to keep him," said Jenas. "At one point, it was looking like he was going to leave but that is a testament to the way he's played and developed. He is the rock in that defence and, if he's not there, that's when you have a chance.
"He could probably get into most top sides quite easily. His reading of the game, understanding, pace, strength, agility ... it's impressive. [And] as Winston gets older, he is one of those players who will get better, start to see the game a lot better."
West Ham coach Slaven Bilic agreed, telling the Herald on Sunday earlier this season that Reid's best years were "still to come" and he could "become one of the best".
According to Jenas, the next step for Reid will be maintaining the level that has put him in the spotlight.
"It's about consistency for Winston now. He's reached a level where he has made people stand up and watch, and see what he is about. Now the question is, can he maintain it? Can he continue to do this for another season or two?
"If he can, someone will probably come and take him. Then the question will be, can he do it at the next level which will be Champions League and so on? He could definitely do it.
"West Ham are up there right now but if a big, big team came in for Winston, it would be hard for him to say no."