Northampton Saints flanker Tom Wood says becoming Premiership champions in 2014 was "probably the worst thing to happen" to the club.
Saints are 10th in the table, not yet safe from relegation, and will miss the play-offs for the third season running.
"On the back of winning it, people downed tools and thought we had the winning formula," Wood said.
"It's not just this last few weeks, not just this season even - it's been a slippery slope for a number of years."
England international Wood, 31, joined Northampton from Worcester in 2010 and has played 113 Premiership games for the club.
A groin injury kept him out of Saturday's 63-13 home thrashing by Saracens, who have put 237 points past them in four meetings this season.
Speaking on BBC Radio Northampton's Saints Show, Wood said: "I actually believe winning the league was probably the worst thing to have happened to us as far as our development and evolution as a team was concerned.
"We stood still, failed to keep pushing the boundaries and looking for new ways to improve as a team and things have slowly slid since then.
"That togetherness, team spirit, buy-in, understanding of one another, synergy and belief in the regime and everything about it is what makes great teams - and we don't have that at the minute."
'We could have a dramatic turnaround'
The sacking of long-serving director of rugby Jim Mallinder in December has seen Alan Dickens and Alan Gaffney step in until the end of the season, with New Zealander Chris Boyd taking charge from August.
Wood says he will definitely be at Franklin's Gardens for the 2018-19 campaign as they enter a new era.
"We're just at a point now where we are hopefully at rock bottom and we can turn it around and start again next season.
"The opportunity for a clean slate - I can't wait to hear a new voice with a vision that we can buy into and just rip forward with.
"I think there's a lot of players that feel the same way and we could have a dramatic turnaround on the back of it with the quality we've got."