The 22 year-old goalkeeper spent the majority of his four-year senior contract at the Blues on loan at Football League clubs, before moving to Joe Dunne's side permanently
Sam Walker has signed for League One side Colchester United from Chelsea on an 18-month permanent deal, after spending two six-month loan spells with the U’s.
The goalkeeper originally signed for the Essex club on 14 January 2013 until the end of last season, and was re-signed on another six-month deal in July.
And, after his recent spell at Colchester ended on Sunday, U’s boss Joe Dunne was pleased to capture the 22-year-old permanently following a series of eye-catching recent performances – including a man-of-the-match showing against MK Dons on New Years Day.
"I'm delighted that we've signed Sam for the next eighteen months,” Dunne told Colchester's official website.
"He is another young and hungry young footballer who has decided to come here and play, which is great testament to what we are doing here at Colchester United.
"He has done fantastically well for us over the past year but he is still improving and will get even better in the right environment for development.
"He will certainly have that here and he has a great support network, with our goalkeeper coach George Bankole and the other keepers he works with every day."
Walker signed for Chelsea’s academy in 2007 after coming through the ranks at Millwall, and was involved in the Blues’ FA Youth Cup triumph in 2010 - with the side only conceding once on their way to the final.