"I'm not mad," Avril said in an interview with The Associated Press about 40 minutes before Monday's 4 p.m. ET deadline to get a long-term deal done. "Business is business. You can't take it personal."
Avril will stay in Detroit as a franchise-tagged defensive end for at least one more season with a $10.6 million contract.
"While we are disappointed that we could not execute a long-term deal, we do look forward to having Cliff with us this season under the terms of the franchise tender," Lions president Tom Lewand said in a statement released by the team.
Lewand said the team had "extensive discussions" with Avril and his representative.
Avril wasn't encouraged by the tone of negotiations Sunday night and Monday morning.
"There was a stretch of talks, but I knew in my head it wasn't going to happen," Avril told the AP.
The 26-year-old Avril was hoping to be rewarded with a long-term contract for being a consistent playmaker for an improving team.
He is the only NFL player with at least 19½ sacks, nine deflected passes, seven forced fumbles and four fumble recoveries the previous two years.
When the Lions snapped their 11-season postseason drought last year, Avril had career highs with 11 sacks, six forced fumbles and three fumble recoveries. He has had 30 career sacks and 14 forced fumbles since 2008 when Detroit drafted him out of Purdue in the third round.
Another team could've negotiated and extended an offer to Avril, but compensation would be a pair of first-round picks to sign the franchise-tagged player.
"It's definitely restrictive," Avril said in June.
Avril, though, has the benefit of a short-term windfall from a one-year deal worth the average of the five highest-paid players at his position
"To go from making the league minimum to that is not bad, but still you want a long-term deal," Avril said last month. "I feel like I was a part of this team while we were not doing so well and 0-16. I want to be a reason why we're getting better."
Buffalo gave defensive end Mario Williams a $100 million, six-year contract -- with $50 million guaranteed -- when he hit the market this year with fewer than 10 sacks the past three seasons and 53 over his six-year career.
Arizona rewarded defensive end Calais Campbell this offseason with a $55 million, five-year deal after he had no more than eight sacks the last three seasons and 21 in his four-year career.
Avril knows he could cash in next year, when he potentially could be an unrestricted free agent after another productive season.
"I could, but you have that risk of getting hurt, that risk of your value going down," he has said. "And, they told me to do that last year. You can't keep doing that for the next 10 years. I wanted a deal last year, too, and they told me to go out and perform and we'll try to, I guess, take care of you in a sense.
"It goes back to being a business. They can do whatever they want -- obviously."