Without three front line locks, the Chiefs have sent an SOS to the retired Ross Filipo.

Scans yesterday confirmed Michael Allardice's season was over after he ruptured the medial ligament in his left knee against the Hurricanes, while Michael Fitzgerald will need more time to heal from a badly corked thigh he suffered in the same game.

All Black Brodie Retallick is still out with a shoulder injury and won't be back for another two weeks.

Much to coach Dave Rennie's delight, forward pack leader Matt Symons has been cleared to return from a concussion but his second row partner in the starting side against the Bulls on Friday is yet to be confirmed.

Rennie said the likely option would be the uncapped Brian Alainu'uese, a 135kg man mountain who has played a handful of games for Waikato in the ITM Cup.

Then there's the issue of a bench replacement.

After witnessing the consequences of having to play captain Liam Messam and flanker Liam Squire in the second row, Rennie has called on 36-year-old Filipo who last year said goodbye to first class rugby after nine seasons with Wellington.

He trained with the team today and said he was originally rostered to take part in television coverage of the game as a sideline commentator.