The Saints captain was selected as one of three hookers by head coach Warren Gatland and he will lock horns in the Premiership final against Leicester at Twickenham with his England and Lions rival Tom Youngs.
Hartley lost his England starting place to Youngs this season - but he is not prepared to be written off as anybody's understudy before the Lions even leave for Australia.
"I think a few people think I am in the Lions squad to cover the third hooker place (behind Youngs and Richard Hibbard)," Hartley said.
"I see this weekend as a chance to push myself forward. I am going there to win a trophy for the club but it is an opportunity to play well and put my hand up.
"With rugby you understand that injuries happen and selections don't always go your way but you have to bide your time.
"Like Arnie said 'I'll be back'. I am not done. Everyone has their time in the sun and I am here for the long game."
While the Lions is a strong personal motivation for Hartley, it is the opportunity to bury years of knock-out heartache that will drive Northampton on.
Hartley has lost four Premiership semi-finals with Northampton and the 2011 Heineken Cup final, which was the most painful of all the defeats.
The Saints led 22-6 after a sublime first 40 minutes at the Millennium Stadium but Leinster, inspired by Jonathan Sexton, staged a remarkable comeback to win 33-22.
"I have had some good times here but the disappointment of losing four consecutive semi-finals and the Heineken Cup final, and losing them in the fashion we have, is heartbreaking," Hartley said.
"You start pre-season with these lads, you all become best friends and you work together. You lose away at Gloucester together and you have the horrible bus ride home.
"But then you win the next week. You go through thick and thin with these lads. The prospect of going to Twickenham with your mates, playing in front of 85,000 and winning a trophy at the end is huge.
"I just don't want this weekend to be another one of those heartbreak games."
The challenge for Northampton, who have not been the models of consistency this season, is to back up their stunning semi-final performance against Saracens.
Northampton had not beaten any of the top three - Saracens, Leicester or Harlequins - but they surged into a 17-0 half-time lead, inspired by thunderous performances from Hartley and Samu Manoa.
Steeled by memories of Leinster's Heineken Cup comeback, Northampton held off a Saracens revival to win 27-13 and end their semi-final hoodoo.
"No-one was giving us a chance. They were top seeds, they had justified their top four position and we had limped in," said Hartley
"What we did well were all the givens you need to succeed in knockout rugby - enthusiasm, intensity and playing for a full 80 minutes and we backed it up with an appropriate game plan.
"We proved a few people wrong. We have to do that again."