Kevin Costner's time with the hit Paramount series 'Yellowstone' could be coming to an end.

'Variety' quoting sources reports that Costner could potentially exit the series on which he has played John Dutton since its launch in 2018.

The issue seems to be Costner's shooting schedule, with the actor being available for fewer days as the show has progressed. Sources also say discussions are underway for a new expansion of the 'Yellowstone' franchise that would feature several characters from the mothership show, with Matthew McConaughey in talks to star.

"We have no news to report. Kevin Costner is a big part of 'Yellowstone' and we hope that's the case for a long time to come," a Paramount Network spokesperson said in a statement quoted by 'Variety'.

"Thanks to the brilliant mind of Taylor Sheridan," the spokesperson added, "we are always working on franchise expansions of this incredible world he has built. Matthew McConaughey is a phenomenal talent with whom we'd love to partner."

Reps for Costner and McConaughey did not immediately respond to requests from 'Variety' for comment.

'Yellowstone' has proven to be one of the most popular shows on television during its run, with the show drawing massive ratings for Paramount Network each season. It led to Paramount signing a sizable overall deal with series co-creator Taylor Sheridan, who has since expanded the franchise with the prequels '1883' and '1923', the latter of which is currently airing its first season on Paramount+ with a second season already ordered.

Sheridan has also been at work on a new spinoff centred on the historic 6666 ranch in Texas.