Kennett wrote to the Herald Sun newspaper that "the tribal nature of the game drives our emotions and yesterday, in my frustration, I wrongly singled out Alastair for what was a team result for which we all must accept irresponsibility and be challenged to do better, week on week.
"I sincerely apologise to Alastair Clarkson and his family for the grief I have caused them."
Speaking later on Tuesday, Kennett said he tried to make direct contact with Clarkson.
"I tried (to speak to Clarkson on the phone) but he doesn’t answer his phone and I then sent him an SMS," Kennett said.
"Then I rang up Stuart Fox at the club and sent through a copy of my apology and said I’d tried to get to Alastair and would he please deliver it to Alastair. I’ve done what I can."
Earlier, veteran midfielder Brad Sewell said Kennett's call was "way off the mark".
Sewell said on Tuesday Clarkson's message was still getting through to his players, insisting he had ignored Kennett's controversial comments after the Hawks' 10th straight loss to Geelong on Monday.
"I didn't take any notice of him whatsoever," Sewell said of Kennett.
"We've had a number of assistant coaches come into the organisation and they've added so much to the group at the moment as well, so there's no doubt whatsoever that [Clarkson's] voice is still being heard."
Sewell expected Kennett would continue to freely express his opinions about Hawthorn in public, but said the club would focus on its future rather than its past.
"There's no doubt [Kennett] did some terrific things for the club over his tenure and that sort of goes without saying," he said.
"But at the moment we've quickly moved on from things that have happened in the past and we'll keep going forward."
Asked about Kennett's criticisms of the Hawks' tactics under Clarkson, Sewell said the fact they had made the 2011 preliminary final and last year's Grand Final since their 2008 premiership showed they were "pretty sound" tactically.
"I think our performances over the past couple of years at the pointy end of the season sort of speak for themselves," Sewell said.
He said Clarkson had a "good relationship behind closed doors" with Kennett.
"I don't know that 'Clarko' himself would pay too much attention to what's said externally regardless of who that comes from," Sewell said.
"He's got a terrific network and terrific support around him and that's all that matters to us."
Sewell said the Hawks relished their rivalry with Geelong despite not having beaten the Cats since the 2008 Grand Final.
"The thing is they're always so close, they're such great games to be a part of, they really are," Sewell said.
"They're brutal contests and 10 is quite a number now."
Sewell said the Hawks' inability to fully capitalise on their dominance in the first half of Monday's game had been a significant factor in their seven-point loss.
Hawthorn now has six days to prepare itself for its round two clash against West Coast at Patersons Stadium on Sunday, while by then the Eagles will have had more than two weeks off since their round one loss to Fremantle.
Hawthorn has won just one of its past nine games against the Eagles in Perth, but Sewell said neither Patersons Stadium's slightly longer and narrower dimensions nor the Eagles' longer break held any fears for the Hawks.
"The short preparation … just means that we won't train as much during the week and there will be a bigger emphasis on recovery," Sewell said.
"We've played well over there in the past and the dynamic of our side certainly won't be too different to that. So it's not a huge issue for us."
Sewell said selection decisions on skipper Luke Hodge (knee) and former Bulldogs defender Brian Lake (calf) would be made later this week.
He said Lake was "certainly" a chance to return from injury against the Eagles, but stressed the Hawks' defence had been "super" against the Cats in his absence.
Sewell agreed it would be a big ask to bring Hodge back in against the Eagles given his interrupted pre-season.
Nick Bowen covers Hawthorn news for AFL.com.au. Follow him on Twitter: @AFL_Nick
Sewell said on Tuesday Clarkson's message was still getting through to his players, insisting he had ignored Kennett's controversial comments after the Hawks' 10th straight loss to Geelong on Monday.
"I didn't take any notice of him whatsoever," Sewell said of Kennett.
"We've had a number of assistant coaches come into the organisation and they've added so much to the group at the moment as well, so there's no doubt whatsoever that [Clarkson's] voice is still being heard."
Sewell expected Kennett would continue to freely express his opinions about Hawthorn in public, but said the club would focus on its future rather than its past.
"There's no doubt [Kennett] did some terrific things for the club over his tenure and that sort of goes without saying," he said.
"But at the moment we've quickly moved on from things that have happened in the past and we'll keep going forward."
Asked about Kennett's criticisms of the Hawks' tactics under Clarkson, Sewell said the fact they had made the 2011 preliminary final and last year's Grand Final since their 2008 premiership showed they were "pretty sound" tactically.
"I think our performances over the past couple of years at the pointy end of the season sort of speak for themselves," Sewell said.
He said Clarkson had a "good relationship behind closed doors" with Kennett.
"I don't know that 'Clarko' himself would pay too much attention to what's said externally regardless of who that comes from," Sewell said.
"He's got a terrific network and terrific support around him and that's all that matters to us."
Sewell said the Hawks relished their rivalry with Geelong despite not having beaten the Cats since the 2008 Grand Final.
"The thing is they're always so close, they're such great games to be a part of, they really are," Sewell said.
"They're brutal contests and 10 is quite a number now."
Sewell said the Hawks' inability to fully capitalise on their dominance in the first half of Monday's game had been a significant factor in their seven-point loss.
Hawthorn now has six days to prepare itself for its round two clash against West Coast at Patersons Stadium on Sunday, while by then the Eagles will have had more than two weeks off since their round one loss to Fremantle.
Hawthorn has won just one of its past nine games against the Eagles in Perth, but Sewell said neither Patersons Stadium's slightly longer and narrower dimensions nor the Eagles' longer break held any fears for the Hawks.
"The short preparation … just means that we won't train as much during the week and there will be a bigger emphasis on recovery," Sewell said.
"We've played well over there in the past and the dynamic of our side certainly won't be too different to that. So it's not a huge issue for us."
Sewell said selection decisions on skipper Luke Hodge (knee) and former Bulldogs defender Brian Lake (calf) would be made later this week.
He said Lake was "certainly" a chance to return from injury against the Eagles, but stressed the Hawks' defence had been "super" against the Cats in his absence.
Sewell agreed it would be a big ask to bring Hodge back in against the Eagles given his interrupted pre-season.
Nick Bowen covers Hawthorn news for AFL.com.au. Follow him on Twitter: @AFL_Nick
