Leicester boss Richard Cockerill believes Northampton face a huge challenge in defending their Aviva Premiership title.
The Saints won the trophy when they beat Saracens in last season's final at Twickenham and also secured a narrow one-point victory over the Tigers in their semi-final at Franklin's Gardens.
But Cockerill feels Northampton will now have to prove in every match why they are the champions.
"You've got to back it up," he told the Leicester Mercury.
"That was the challenge for Quins when we lost to them. Now Saints have got to back it up. That's just the nature of it.
"When you are champions, it is different - achieving something is hard and it's great, but backing it up year on year is the thing that we pride ourselves on.
"Saints have been a good side for the last four or five years, they have been in semi-finals and finals and not quite made it.
"In the snapshot of time, they are champions. They have got to defend that title every time they play now."
Northampton's 21-20 victory over Leicester also ended the Tigers' 10-game unbeaten run against them.
That includes the 2013 Premiership final in which Leicester's triumph secured them their 10th title.
"The reality is, they are champions," added Cockerill.
"We drew 19-19, we beat them by six, they beat us by one.
"Those were the three games in the season. It's that tight.
"In the final, they could easily have lost it. In the end, the TMO decision was pretty subjective.
"They'll know that, you just get on with that. The rivalry is the rivalry, it's great.
"It's just a shame we don't play them at Welford Road until the last day of the season."