Blues head coach Sir John Kirwan has made five changes to his starting XV for Saturday night's clash with the Highlanders in Dunedin.
With Keven Mealamu away with the All Blacks earlier this week, James Parsons has been given the nod at hooker while lock Anthony Boric makes just his second start of the season in place of Culum Retallick.
"Our whole lineout was here with Ali being back and Anthony starting so we've just got a little bit selfish really and said JP can throw all week and Kevvie can come off the bench. It gives us a little bit more organisation and confidence in what is a critical game," Kirwan said.
"AB is ready to go, he's had his challenges, he's an All Black lock and Red (Culum Retallick) is on the bench so it's a great opportunity for AB to step up and show us what he's got."
Impressive young All Black prospect Steven Luatua has overcome a neck injury to start at blindside flanker, while scans on Luke Braid's groin have come back clear so he will start on the openside.
In the backs, Baden Kerr makes his second start of the season in place of Chris Noakes who is dealing with some family issues, while Waisake Naholo also gets a rare start on the left wing ahead of George Moala.
"It's time to give Waisake a crack at it. He's deserved it, he's worked hard and we know what George can do so it's a little bit of a change up," Kirwan said.
Kirwan said he was looking forward to playing on a dry track under the Forsyth Barr Stadium roof on Saturday night in what shapes as a crucial game for the Blues' playoff prospects.
"For us it's a case of if you don't understand the importance of this week then you're playing the wrong game and our boys do. We're excited about the challenge," Kirwan said.
"We know the Highlanders have just been missing so they can make their season by beating us. We can't let that happen, we've got to put our season back on track and get back up the points table and stay in touch. If we do that this weekend then we're back in contention for the top six so there's a lot riding on it."
The Gordon Hunter Memorial Trophy is also on the line on Saturday night, honouring one of the characters of Otago Rugby who was also in the unique position of having coached both the Blues and Highlanders.
15. Charles Piutau,14. Frank Halai,13. Rene Ranger,12. Francis Saili,11. Waisake Naholo,10. Baden Kerr,9. Piri Weepu ,8. Peter Saili,7. Luke Braid,6. Steven Luatua,5. Ali Williams,4. Anthony Boric,3. Angus Ta'avao,2. James Parsons,1. Tim Perry
Replacements : 16. Keven Mealamu,17. Sam Prattley,18. Culum Retallick,19. Brendon O'Connor,20. Jamison Gibson-Park ,21. Marty McKenzie,22. Jackson Willison