On Sunday, he will lead the side from the fly half position, with Freddie Burns named amongst the replacements.
Mike Tindall will partner Henry Trinder in midfield, with Charlie Sharples also returning to the starting line up.
Nick Wood is back at loose head prop, and Tongan international Sila Puafisi will make his first full start at tight head.
In the back row, Matt Cox and Matt Kvesic will line up against their former club. Cox comes in for Sione Kalamafoni who picked up an ankle injury against Edinburgh last weekend.
Talking to the local media at the club's midweek media session, Davies knows that Worcester, although still looking for their first win, have been competitive in most of their games to date.
"It's going to be a difficult encounter for us because you look at Worcester, and how they've played, and they've been in games for long periods before falling away late.
"But they'll be aware of that, and they'll have worked on that. They'll be a tough nut to crack, and we have to be in the right frame of mind, which means not just being physically ready for the challenge but also being prepared to play rugby, our style of rugby.
"That means going out there to win the game, not to just hang in there. Worcester will approach the game in their own way, we have to make sure that we are right."
Rob Cook; Charlie Sharples, Henry Trinder, Mike Tindall, Jonny May; Billy Twelvetrees (capt), Jimmy Cowan; Nick Wood, Darren Dawidiuk, Sila Puafisi; Elliott Stooke, James Hudson; Matt Cox, Matt Kvesic, Ben Morgan
Huia Edmonds, Yann Thomas, Shaun Knight, Tom Hicks, Akapusi Qera, Dan Robson, Freddie Burns, Martyn Thomas
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