The Melbourne Rebels feel the Super Rugby defending champion Highlanders are playing better than when they won the title.
While the Rebels are off to their best season start, coach Tony McGahan acknowledges that facing the Highlanders at AAMI Park tonight is a big step up.
"The Highlanders have playedgreat rugby this year," said McGahan.
"We really feel that they've probably gone up another level with their combinations and their confidence in what they do and they gather that from winning a championship."
Melbourne didn't meet the Highlanders last season but their previous two clashes have been tight, with three points or fewer splitting the teams.
After shoulder surgery Stirzaker made his first appearance of the year in last round's win over the Sunwolves with some late minutes off the bench.
"Ben's been doing a really good job and Stirzy's only just come back into it and also the fact that we travelled in the first few weeks denied him some training time with the side," McGahan said.
The teams are both 3-1 for the season to both sit second on their respective country ladders.
While the Rebels beat Sunwolves, the Highlanders held out the fast-finishing Waratahs.
McGahan said that in the past his team would have been happy just to be competitive against a team of the Highlanders' quality - but not any more. "The mindset for us has slowly changed from giving them a test to actually expecting a result and that's the big difference in this season."