Blues centre Rene Ranger has been asked by coach John Kirwan to step up and play a leadership role in Super Rugby this season.  

Following the loss of Ma'a Nonu to the Highlanders the Auckland side find themselves short of experience in the backline and Kirwan is backing the unpredictable Ranger to take charge of the backline as the Blues seek to improve on a woeful season last year.

Kirwan said that Ranger has been particularly impressive during the Blues' pre-season training and added that he will rely on the explosive back to show the way behind the scrum this season.

"He's leading the backline and doing a great job," Kirwan told allblacks.com.

Ranger's pace and ability to break the line has seen him used in a number of different positions over the years, but Kirwan is keen to see him focus on his role in the midfield to give the backline some solidity.

"He should be a key focal point in our backline that's not to say down the line he might have to cover other positions, but for me he has to cement our backline," he said.

The Blues coach said that pre-season training has been positive so far, with plenty of hard work going in as he and defence coach Graham Henry prepare the squad for the start of the season.

"This week has been our first technical week so it has been really intense for them and it has been a good week.

"There's quite a lot of learning to be done in the next two weeks. They're positive, they're fast learners and I think we are all on the same page," he said.

Kirwan said that he would not rush All Blacks lock Anthony Boric back from injury too quickly as he realises just how valuable the big tight forward will be to the Blues' campaign.

"I think he's a fantastic Blues man. He has come through a pretty big injury so there's no pressure on him back to play.

"He's right on target, he's looking fantastic but I just want to make sure that when he comes back he's coming back to stay and that he achieves all the goals that he still wants to achieve in the game," he said.