The Glasgow-born giant second row remains one of the finest lineout operators in the English game and has now agreed a new contract that will keep him at Warriors until 2013 and mean he has played over a decade at the club.
Gillies has excelled for Worcester this season in the RFU Championship to cement a key role in the pack and Head Coach Richard Hill believes the lock is now playing some of the best rugby of his entire career.
Hill also hailed his outstanding attitude, leadership skills and unwavering professionalism as crucial elements at Warriors.
"Craig is playing as well now as he has ever done and remains a real force in the game," said Hill. "He also keeps himself in fantastic shape, which is underlined by the huge number of games he has already played for Warriors.
"This season he has been dominating the lineout for us, controlling restarts, making big tackles and really carrying strongly as he continues to show his talent.
"He truly is an outstanding professional and a wonderful example for all younger players to follow in their rugby career. He is a delightful man to work with and I could not wish for a more motivated, helpful and mature player in the squad.
"Craig brings vast experience to the team and his attitude is perfect for this club - ultimately, he is Worcester through and through. He will always put his body on the line for Warriors every week and wants the club to be a success this season and also to build for the future."