Indeed, he even had to break from training to sign the paperwork that seals the transfer and he is now available to play against Sheffield United at the weekend.
MD Paul Aldridge confirms: "We welcome Kevin back to the club and we look forward to him settling in quickly."
Plumstead born Kevin started his professional career at Upton Park but was unable to break through into the first team and left for Swindon Town for £30,000 in August 1992.
The 30 year-old midfielder, who has 32 caps for Northern Ireland, left Swindon for Maine Road just over six years ago for £1.25m.
He has signed a three year contract at Upton Park.