Saturday's topsy-turvy 30-24 loss to the Highlanders in Dunedin snapped the tenuous positivity surrounding the side following their victory over the Brumbies at Eden Park the week before, and they have a mammoth task next in the form of a struggling Crusaders team in Christchurch next Saturday.
Kaino, probably the Blues' most consistent performer this season, has started every match except the defeat to the Hurricanes in Palmerston North, which he missed due to concussion.
He is averaging more than 75 minutes per match and, as a leading All Black in World Cup year, is due for a rest, according to Kirwan, who will make a final decision today or tomorrow.
"He's got high minutes. We've got to rest them all so I have to look at how they scrub up," Kirwan said.
The defeat to the Highlanders was another one that got away and will probably sound the death knell on the Blues' play-off hopes. After conceding 24 points in the first half through former Blues players Malakai Fekitoa, who crossed the line twice, and Waisake Naholo, the Blues took a more direct route and got close thanks to two tries from replacement hooker Keven Mealamu and one to powerful midfielder George Moala.
The Blues had their opportunities in the first half but, like so often this season, they were squandered.
"It was a case of not winning the little battles," Kirwan said. "They had more 'want' that us and I think we just thought it would happen rather than making it happen. The kick-pass from Daniel Bowden summed it up - everyone stood off rather than taking ownership of it and scoring the try.
"In the second half we reversed that and looked like taking the game at one stage but a couple of critical things didn't go our way."
Some of the option taking was faulty too. First-five Bowden had a four-on-one overlap outside him when he kicked instead of passed, and halfback Jamison Gibson-Park should have backed himself to score against a stretched Highlanders' defence in the first half, rather than passing.
Francis Saili was sharp in the midfield after replacing Pita Ahki, who tore a hamstring, and he is likely to start against the Crusaders, who have drifted down the points table after losing two derby matches. Their latest defeat, a 26-9 reverse to the Chiefs at AMI Stadium, was particularly lacklustre, but Kirwan was in no doubt as to which team would be favourite.
"They're probably not going through as tough a time as we are. It's another big game for both teams. We can't drop another game and they need to stay in touch with the leaderboard so it makes for another big derby."
The Crusaders are 10th with 19 points and the Blues, who have won one match and lost eight, 13th with 11 points. The Stormers, who have 26 points, are currently occupying the sixth and final playoff position.
"We've still mathematically got a chance [of making playoffs] but I don't think we can drop any more games," Kirwan said, adding that he wouldn't concede defeat in terms of his future at the franchise.
"I'm not the type of person who wants to not finish what I've started, but that's out of my control... I trust what the club is doing and the board and [chief executive] Michael [Redman] will go through a process and I'll leave it at that at the moment."
