On loan from Gloucester for the rest of the season, Walker replaces the injured Chris Latham at full-back.
Darren Morris is brought back into the starting XV against his former club, while wing Miles Benjamin is named among the replacements after recovering from a broken leg.
Director of rugby Mike Ruddock makes a total of five changes to the starting line-up that faced Bath last weekend, with Morris being joined by Chris Fortey in the front row, Craig Gillies making his return at lock and Matt Powell gaining the nod at scrum-half.
"My plan is to introduce fresh players into the front five before unleashing the likes of Rawlinson, Mullan and Lutui off the bench early in the second half at Leicester," said Ruddock.
"Leicester are going to be direct and be very physical with their set-piece, breakdown skills and big runners. Our defence has got to be spot-on.
Worcester Warriors (v Leicester Tigers, Welford Road, Saturday 3pm)
15 Willie Walker
14 Rico Gear
13 Dale Rasmussen
12 Loki Crichton
11 Marcel Garvey
10 Joe Carlisle
9 Matt Powell
1 Darren Morris
2 Chris Fortey
3 Tevita Taumoepeau
4 Will Bowley
5 Craig Gillies
6 Tom Wood
7 Pat Sanderson (c)
8 Kai Horstmann
Replacements
16 Matt Mullan
17 Aleki Lutui
18 Greg Rawlinson
19 Netani Talei
20 Ryan Powell
21 Alex Grove
22 Miles Benjamin
