Griffiths says he has a great working relationship with Ruddock

Griffiths spent the past year as head coach at Doncaster RFC, but leaves mid-way through his two-year deal.

Ruddock, who took the reins at the Warriors in May, had Griffiths as his assistant when he was in charge of both Wales and Newport Gwent Dragons.

"It is a brilliant opportunity and I'm looking forward to working with Mike again," said Griffiths.

"Mike is very easy to work with and respects you as a coach and as a person. He lets you get on with it and isn't always looking over your shoulder.

It is a massive challenge we have at Worcester Clive Griffiths

"I'm still waiting to sit down with Mike and find out exactly what my role is, but I'm expecting it to be very hands on."

During their time at the Dragons, in the inaugural season of regional rugby in Wales, Ruddock and Griffiths took them to the verge of the Celtic League title.

Ruddock then left to take over from Steve Hansen as national coach, and, along with Griffiths and Scott Johnson, led Wales to their first Gram Slam in 27 years in 2005.

Ruddock left his post as national coach in 2006 and had been out of rugby until his appointment as Worcester coach in May.

Griffiths enjoyed a successful season at Doncaster, leading them to third in National Division One, and is relishing the chance to help revive Worcester, who only escaped relegation from the Premiership on the final day of the season.

He said: "It is a massive challenge we have at Worcester.

"I compare it to my time at Doncaster, where I arrived at the club the year after they had been involved in a relegation battle.

"I knew we had to turn things around pretty rapidly to avoid that sort of situation again and as it turned out we had a fantastic season.

"Up until the last two months of the season we were involved in a promotion battle, so if we have the same sort of results at Worcester I'll be very happy."

Griffiths won one cap for Wales in 1979, coming on at full-back for JPR Williams.