Blues coach Tana Umaga is in no mood to rush All Black midfielder Sonny Bill Williams back into Super Rugby.
Williams is still recovering from surgery on his achilles that he snapped during his campaign with the New Zealand Sevens team at the Rio Olympics.
The 31-year-old was training with the squad today and wants to be back playing by week six of the competition but his coach is keeping his cards close to his chest.
"I think our medical staff are really mindful of loading too much on him too early.
"Because he hasn't done a lot of sprinting and then all of a sudden trying to do that too soon, it's not so much the achilles it's other parts of his body that have to cope with it so we'll just a wait and see," Umaga said.
Umaga was impressed with Williams' progress so far though.
"He's hitting all the marks that he needs to, we just want to make sure that we don't rush him back and that he falls over again too early so we just want to make sure he's 100 per cent."
Meanwhile Umaga has been forced to drop first five Ihaia West to the bench in favour of Welshman Piers Francis for this weekend's match against the Crusaders in Christchurch.
West struggled to control the game for the Blues against the Highlanders on Saturday while Francis made an immediate impact coming off the bench.
"We are looking for a much more competitive effort at set piece, and with more accuracy in core skills. You cannot be competitive in this competition with the error rate that we committed last week," Umaga said.
Other changes to the side include moving Jimmy Tupou from lock to blindside flanker while Jerome Kaino moves into the number eight jersey.
Gerard Cowley-Tuioti comes back in as the starting lock to partner All Black Patrick Tuipulotu in the second row.