One of the most potent attacking weapons in the game, Clarke pulled up injured during the 21-19 win over the Brumbies in Canberra last weekend that guaranteed the Blues top spot in the standings at the end of the regular season.
Clarke will definitely miss this week's trip to Sydney to face the resurgent NSW Waratahs but assistant coach Daniel Halangahu said there was some hope that he might be available for the semi-finals or final.
"He's not available this week. Beyond that, with the size of his legs, maybe they heal faster than others," he told the NZ Herald on Tuesday.
"It is bad timing, especially the way he is playing and the way he started that match. He's an important part of what we're doing. We feel for him. Injuries are a horrible part of the game.
"How he pulls up by the end of this week will be important to see if it's as bad as some hamstrings are."
That optimism would have been music to the ears of the All Blacks selectors, who will be banking on Clarke to be a big factor when Ireland visit New Zealand for three Tests in July.
Despite having locked up home advantage throughout the finals and earning the opportunity to rest some players, the Blues will be crossing the Tasman determined to extend their winning streak to 13 matches.
"We're going to Sydney and we're going to win. That's been the strongest message around here today," added Halangahu, a former Waratahs five-eighth.
