Although his time has been divided between club and country training commitments during the Six Nations, Clark has been captaining the Saints in the LV= Cup and Aviva Premiership Rugby in recent weeks and leading by example.
The flanker's commitment was typified in his reaction to Ben Nutley's last minute winning try against London Irish a fortnight ago and he says that he is determined to skipper the Saints to the LV= Cup final.
"It's a competition we're keen to progress in," he said. "We've worked hard to get to the semi-final and it's a good chance for us to get within reach of some silverware.
"We play every game to win and momentum's important. We've got to keep winning.
"We really like playing at the Gardens. We like it when it's full and the atmosphere's great here when the fans get behind us."
The Scarlets will come to Franklin's Gardens on the back of two bonus point wins in the Pro 12, and Clark said that Sunday's game represents a tough challenge for the Saints.
"We know from playing them in the Heineken Cup that it's going to be a hard game," he added. "We were disappointed with the home game and they're one of the top Welsh sides, so we're going to be up against it.
"They're missing a few and so are we, but the strength in depth of the squads will come through this weekend. Obviously depth is something you need in any squad and it'll be on display this weekend."
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