The news Alan Curbishley has had enough at West Ham is no great surprise. Today's announcement that he has resigned as manager has been coming for some time and the transfer deadline day sale of George McCartney was the final straw for him.

Only two weeks ago a close friend and colleague told me: "I don't know how much more Alan can take. He's had his bellyful and we're afraid he could say 'enough is enough' at any time."

That friend's fears were realised today, justifying the bookies' pre-season decision to make Curbishley, born and bred in the east end of London, the favourite in the managers' sack race.

Curbishley felt humiliated and embarrassed by the sale of McCartney to Sunderland on Monday. He had earlier twice categorically stated that no-one else would be sold before transfer deadline day.

In the end he was wrong and, in his eyes, the rug had been pulled from under his feet. It was time to go although, in truth, the seeds of doubt had been growing for some time.

It all started so well back in December 2006 when he succeeded Alan Pardew as West Ham manager.

Curbishley himself felt refreshed. He had enjoyed several months off following his amicable departure from Charlton after almost two decades there and was ready for a fresh challenge.

West Ham wanted him and the time was right. The new Icelandic consortium, headed by chairman Eggert Magnusson, had promised a significant cash injection and Curbishley relished the challenge.

The immediate challenge was keeping West Ham in the Premier League but Curbishley said: "If we can do that I can promise exciting times ahead for the fans."

So it proved. It went right down to the wire but West Ham survived, beating Manchester United on the final day of the season.

Magnusson had already spent significant funds on attracting quality players to the club and more followed the following summer.

Back in Iceland, though, Bjorgolfur Gudmundsson, chairman and major owner of Icelandic bank, Landsbanki, was beginning to be concerned over what he saw as profligate spending by Magnusson, who was popular with the West Ham fans.

Eventually he bought out Magnusson's five per cent stake in the club and, with the credit crunch hitting hard back home, embarked on a new, more prudent regime. This impacted on Curbishley. "From being up there," he once indicated, "we're now back down there."

Injuries all but wrecked Curbishley's first full season at the helm but his team finished a very respectable 10th. Despite that, though, the fans were not happy.

They felt the football was dull, something which Curbishley later conceded but explained that his hands had been firmly tied by the horrendous injury list.

There had also been reports that the players had lost some respect for their manager and that there had been several angry dressing-room confrontations, most notably with captain Lucas Neill, after Saturday's match against Blackburn.

The defender reportedly told Cubishley that the players had "kept you in the job" and he needed to show more leadership. Some felt that Curbishley's position was further compromised by the arrival of new technical director, Gianluca Nani, from Brescia.

The club, still embroiled in a potentially expensive arbitration procedure with Sheffield United over the Carlos Tevez affair, were set on a prudent financial strategy whether Curbishley liked it or not.

As others spent heavily in the transfer window, West Ham sold Anton Ferdinand, Bobby Zamora, John Pantsil and McCartney for a combined fee of £20million.

Curbishley could see the writing on the wall. He made it known he was against the sale of Ferdinand and, after declaring that was the end of the sales, had nowhere to manoeuvre when McCartney went on deadline day, saying his wife couldn't settle in London. Saturday's 4-1 win over Blackburn means West Ham have made their best start, after three games, for nine years. Curbishley leaves with his reputation and credibility intact while the club will justifiably point to their summer and say they've done good business.

As for the future, Slaven Bilic would be the popular choice and is understood to be keen on the job. As an alternative, Nani could be lining up a replacement back home in Italy.

What now for Curbishley? As one of the most experienced and respected managers in English football, he will surely find another post, if he wants it.

Otherwise he may just walk away completely and perhaps link up with his brother who is in the music business.

At least they should be singing from the same hymn sheet.