In the front row, former Springbok Faan Rautenbach comes in at tight head prop; in the second row Matt Garvey starts alongside Andy Perry; Gary Johnson switches from the second to the back row where he starts at blindside flanker. Kieran Roche takes over at No 8.
Among the backs the experienced John Rudd, Elvis Seveali'i and Seilala Mapusua start at left wing, outside centre and inside centre respectively.
"Matches with Worcester are always dogged and competitive at their home stadium. We expect the Warriors to be preparing themselves for a good run into their upcoming Guinness Premiership fixtures so supporters are promised an entertaining match with good rugby from both teams," said London Irish Head Coach Toby Booth.
15. Peter Hewat (captain); 14. Topsy Ojo*; 13. Elvis Seveali'i*; 12. Seilala Mapusua*; 11. John Rudd; 10. Ryan Lamb; 9. Alfredo Lalanne*; 1. Dan Murphy; 2. James Buckland, 3. Faan Rautenbach*; 4. Matt Garvey; 5. Andy Perry; 6. Gary Johnson; 7. Richard Thorpe; 8. Kieran Roche.
16. Danie Coetzee*; 17. Clarke Dermody*; 18. James Tideswell; 19. Kieran Low; 20. Jamie Gibson; 21. Chris Malone; 22. Peter Richards*; 23. Jamie Lennard.