TORONTO -- Kyle Lowry called it a wasted season. DeMar DeRozan said it was the low point of his NBA career.

The Toronto Raptors headed into a off-season of uncertainty Tuesday after suffering another embarrassing playoff sweep at the hands of LeBron James and the Cleveland Cavaliers.

But this elimination felt far worse than the previous years. And it may have cost coach Dwane Casey his job.

"It's just a terrible feeling of when reality hits you that tomorrow you won't be preparing for work," DeRozan said. "My nine years being in the league, this is probably the toughest, most frustrating, difficult, lowest feeling I've had."

Hopes had been sky-high after the Raptors roared to a franchise-best 59 games to clinch the No. 1 Eastern Conference seed, and Casey's ability to both revamp the team's offensive style and develop his bench made the 61-year-old a front-runner for the NBA coach of the year.

James and the Cavs slashed through all of Toronto's regular-season work in seven quick days, leaving the Raptors still shell-shocked the morning after their humiliating 128-93 blowout in Game 4 of their second-round series.

"It does feel a lot different because we feel we could possibly make the NBA Finals, that was our goal," Lowry said. "For me it was championship or bust, that's what I feel, that's what I always feel, so a wasted year for me."

Neither Casey nor team president Masai Ujiri spoke to the media on Tuesday. The team said they would be available at a later date.

Casey is the most successful coach in franchise history, and the Raptors' record has improved in all but one of his seven seasons at the helm. But there's been a palpable feeling that change is afoot since the Raptors fell to 0-2 in the series.

Beyond the glaring lack of fight in Games 2 and 4, there were questionable moves such as the use of Lucas Nogueira on Monday night. The Brazilian big man, who'd barely seen the floor in the playoffs, turned the ball over and committed a foul during his less than two minutes Monday, and the Cavs closed the half during that stretch with a game-turning 12-2 run.

When asked for his thoughts on his Casey, DeRozan said he's made a habit of staying out of personnel moves.

"My job is to always come back better next year. I just do my job, and that's to come back better. . . and I never question anything else. I let upper management handle that, honestly," DeRozan said.

The four-time all-star, however, credited the coach for the success he's found.

"I've been with Casey seven years. He put the trust in me, he believed in me, he let me be a 21-year-old kid going out there, playing freely," DeRozan said. "A lot of my success, all of my success, I have to credit Casey. No matter what, I'm always going to have the utmost respect when it comes to coach Casey."

Lowry and Casey had butted heads in the past, but the point guard said "I wouldn't ever be what I've become without him as my coach.

"I always believe in him. I believe he's one of the best coaches out there. He's one of the best coaches I've had. At the end of the day, he's still my coach. That's what it is right now."

While DeRozan had trouble pinpointing where it all unravelled against Cleveland, suggesting it's unfortunate the Raptors met the Cavs so early in two consecutive seasons, Lowry said the biggest thing missing was "physical toughness."

"I think we just let them be too comfortable," he said.

Lowry and DeRozan, who between them will make more than US$57 million next season, both said they still believe the team has the right pieces in place. Lowry pointed to the young players such as rookie OG Anunoby, who was one of the few bright spots in the Cavs' series, plus Jakob Poeltl, Delon Wright, Fred VanVleet, and Pascal Siakam.

"Our young guys will continue to get better," he said.

The bench, whose consistent play made them the best in the league during the regular season, faded during the playoffs, other than the Raptors' Game 6 win over Washington.

"I felt pretty confident that we pretty much shredded every bench in the NBA in the regular-season and we just didn't get it done in the playoffs," said VanVleet. "Kind of true to our team in terms of underperforming when it mattered the most. . . We weren't that same special group that we were during the regular season."

The 24-year-old guard and Nogueira are the Raptors' only free agents this off-season. VanVleet also admitted his injured right shoulder bothered him more in the playoffs than he let on. He plans to meet with doctors in New York this weekend to see if his post-season play caused further damage.

"I can kind of be honest about it now. I've been lying to myself for the last two, three weeks because I had plans on playing until June," VanVleet said.

Lowry, who was afforded more rest during this regular-season thanks to the strength of the bench, said his good health was part of his frustration.

"I feel as good as I've ever felt. I feel like I have another two, three months of play. Mental freshness, my body feels great, I was able to just keep going," Lowry said. "It's a little bit frustrating for me because it was a great year in the sense of minutes down, less usage and all of that. I felt like I had a lot more to give."

DeRozan said he probably won't watch basketball for awhile, and instead will let the sting of this shocking ending "marinate."

"Because that's the drive, that's the hunger, that's the motivation that I find within myself to come back better, next year," he said. "The feeling I felt last night, I will feel the same tomorrow, the next day, next day, the next day. I'll feel it, until I can suppress this feeling, until I can get back in the gym."

DeRozan had a roller-coaster season, opening up about his battle with depression that helped prompt a league-wide campaign. He struggled mightily against Cleveland, and was ejected for a Flagrant 2 foul in the third quarter of Game 4.

He said he still believes this group can get to the next level.

"There's always belief," DeRozan said. "I always look at life, not just basketball, the toughest things you go through will turn you into something greater than you could have ever imagined. Whether you believe it in that moment or not. For me I always just have that belief, I don't know how, I don't know why, I just always had that belief of the more crap you go through, the stronger and more resilient you're going to be down the line."