Tom Selleck fans may have uncovered why the acting legend looked worse for wear on his first public appearance since his hit series, Blue Bloods, was cancelled.

After sparking concern earlier this month as he left a gym in Thousand Oaks, eagled-eyed supporters of the 79-year-old actor began to speculate he may have recently undergone surgery as he had large vertical scars on both of his knees.

The apparent knee surgery scars would explain why he appeared to have ‘trouble walking’ back to his car as seen in footage obtained by In Touch Weekly.

DailyMail.com has reached out to the Magnum, P.I. alum’s representatives, but have not heard back at this time.

Selleck has not spoken publicly about undergoing or needing a bilateral knee replacement surgery, also known as a double knee replacement.

Tom Selleck fans may have uncovered why the acting legend looked worse for wear during his first public appearance since his hit series, Blue Bloods, was cancelled

Last summer, his representative denied RadarOnline’s claim that he was suffering from ‘a secret medical crisis that has forced him to use a stunt double while filming Blue Bloods.’

Despite the outlet claiming he was ‘in a lot of pain and agony’ and was working with doctors to ‘learn techniques to alleviate’ his pain, his rep insisted Selleck was ‘fit and vigorous.’

In January 2023, Selleck’s rep also shut down The Daily Star’s allegation that the performer was battling ‘crippling arthritis.’

In response to the article, Selleck’s rep stated that their client was in ‘excellent health.’

Selleck is said to have relocated back to his California ranch with wife Jillie after 14-years of commuting to and from the East Coast to film the show, which was suddenly halted by CBS bosses at the end of last year.

Selleck made no secret over his disappointment with Blue Bloods coming to an end, and after show bosses announced last year that it would stop filming, he said he hoped they would ‘come to their senses.’

Although filming on the show has wrapped, fans can still expect to see the actor for the conclusion of its 14th and final season in October.

And while Tom may be happy to have more time to hit the gym now he is back on the West Coast, he said back in January that he had ‘learned to love’ his busy schedule.

The 79-year-old actor has large vertical scars on both of his knees, most likely from a bilateral knee replacement surgery

Last summer, his representative denied RadarOnline’s claim that he was suffering from ‘a secret medical crisis that has forced him to use a stunt double while filming Blue Bloods’ (seen in 2015)

‘Sometimes the hours are a little harder because I’m older, but so what?’ he told TV Insider. ‘I want to work as long as they’ll have me.’

Selleck, who was previously best known as Magnum PI as well as a stint on Friends, won legions of fans with his turn as Frank Reagan on Blue Bloods, a fictional NYPD commissioner.

He has starred alongside Donnie Wahlberg, Bridget Moynahan and Will Estes since September 2010, and said when the show was axed that fans were sure to react with fury at the decision.

‘CBS will find an awful lot of people aren’t ready to say goodbye to it,’ he said at the time.

‘The show’s more popular than ever, and I think [numbers] will increase with the interest this year. We’re certainly not out of ideas.’

Selleck has come a long way from his most famous role a Magnum PI; seen in 1980

When filming wrapped, a source said Tom was set to enjoy downtime on his 65-acre California ranch that he shares with wife Jillie Mack, 66.

‘He wants to relax on his ranch, walk around his property, spend time with his wife and family, and travel a bit,’ a source told Closer magazine in January.

‘Tom and Jillie can just sit at home, cook, go for a long walk and be very content. He adores Jillie and trusts her to schedule activities or travel plans.

‘He’s looking forward to having more free time to spend with her.’

However, Tom revealed in May that the fallout from the end of Blue Bloods could end up costing him his twilight years on the ranch.

Despite a career spanning decades in Hollywood – including a reported $200,000-per-episode Blue Bloods deal – he told CBS Sunday Morning that he was in jeopardy of falling behind on bills after the show was axed.

Selleck made no secret of his disappointment that Blue Bloods was ending after 14 seasons, bringing time on his role as fictional NYPD Commissioner Frank Reagan

A source previously said Tom is looking forward to spending his twilight years on his Ventura, California ranch with his wife and daughter

‘You know, hopefully I keep working enough to hold on to the place,’ Selleck said, to which CBS correspondent Tracy Smith responded, ‘Seriously, that’s an issue? If you stopped working?’

Selleck said, ‘That’s always an issue – if I stopped working, yeah. Am I set for life? Yeah, but maybe not on a 63-acre ranch!’

The source added to Closer magazine that as Tom moves towards retirement, he is more enamored than ever with both his wife and daughter Hannah, 35, an accomplished horse rider.

The source said: ‘Tom’s very close to Hannah and very proud of her competitive horse jumping career.

‘He hopes Hannah finds love and has children, but he’s not the type of dad to push it.’