Assistant coach Steve Clarke quit Chelsea because he knew there was no chance of him ever being given the top job at Stamford Bridge.
ClarkeÂ enjoyed lengthy spells atÂ ChelseaÂ both as aÂ player and coach but left in September last year when former Blues star Gianfranco Zola asked him to become his assistant at West Ham.
"I think I could have been the manager but I don't think it was realistic that Chelsea would have offered me the job," said Clarke.
His move across London stunned Chelsea as Clarke had previously hinted he would only ever leave the club for a managerial post.
Clarke's initial resignation was rejected by Chelsea but a compensation package was eventually agreed with West Ham that allowed the former right-back to make the switch to Upton Park.
The tough-tackling Scot helped Jose Mourinho win every domestic honour at Chelsea before the Portuguese boss left in September 2007 and Clarke was alongside Avram Grant when the Israeli inspired the Blues to the final of the Champions League last season.
But he found himself marginalised under Grant's replacement, Luiz Felipe Scolari, and jumped at the chance to link up with Zola at West Ham because he knew there was no possibility of him stepping into the hot-seat at Chelsea.
He added: "One of the reasons I left was that there was always the danger I would be labelled as number two at Chelsea. I was there as number two but then somebody else came in, and then someone else, then someone else and then someone else.
"I had to make a choice. Don't get me wrong it would have been a great job to have stayed at Chelsea and been number two. I could have stayed there for the next 10 years, I am sure. But I have personal ambitions, so I just felt I had to leave Chelsea to further my career.
"I made the step to come to West Ham for personal ambitions. Other people have to judge whether I have done a good job or not but I think West Ham are quite happy with what I am doing and Gianfranco is quite happy, so things are good just now."
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