Saturday's 24-11 defeat at Leinster was Ulster's third loss in their last four GUINNESS PRO12 games, meaning they have also lost their last six away games in all competitions.
The result at the RDS Arena left the Ulstermen fifth in the table as Leinster leapfrogged them into the fourth and final play-off spot.
However, Clarke is refusing to throw in the towel on Ulster's title hopes just yet, especially with an important run of fixtures that sees them play teams currently below them in the GUINNESS PRO12 table in their next seven league games.
This run kicks off away at Treviso this weekend and Clarke wants his Ulster troops to make the most of the opportunity in front of them.
"I think this weekend's game is really important to us," Clarke told the Belfast Telegraph.
"It won't define our final position of the season but it will go a long way to establishing us in the top four. Over the next period, we have a run of games that we'd expect, and we've set ourselves a target of accruing, a certain amount of points.
"During that period Ospreys, Leinster, Glasgow and Munster all play each other. We've been to Munster, we've been to Ospreys and played them at home, we've had Glasgow here and we've been to Leinster.
"Those teams have got to come to us now. The only team above us that we have to go to is Glasgow.
"That's at the back end of the season. It's a tough run in our last three league games but two of them are at home and we've got to ensure that we're in a position that we're going into those games competing for one of the top two positions."
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