Confirming the decision, Glenn Roeder explains:
"Nigel came to see me and ask me what the situation was; his contract will not be renewed but he feels he has another season in him - as I'm sure he has - and he will play on.
"But I brought Vladimir Labant in to play at left back eventually and I do not think it is fair for a player of his age to sit on the bench or be in the reserves.
"He was on the verge of quitting after Everton away but thankfully we persuaded him not to - he has been a model professional who has had a brilliant two years here.
"In his career he has probably won more medals than 99% of the players in the game, and, though I understand he wants to play one more season, when I signed Vladimir Labant I took the view that he will be our first choice left back next year.
"I feel it is the right decision for the club - and for Nigel as well.
"It sums him up that after the Everton game, when he was subbed, he was unhappy about his performance and came to see me; fortunately, between the two of us, we talked him out of leaving West Ham.
"Flair players tend to get all the credit, rarely defenders, but when he does make the newspapers it is always for the right reasons, and on the back pages not the front ones."
There will be no shortage of takers for his services, and in the mean time he hopes to play in the remaining five games of the season.
He makes an emotional return to his old stomping ground Highbury later in the month - possibly the last time he will play there in a distinguished career spanning 851 games for Wimbledon, Arsenal, and, in the last two seasons, West Ham.