Casting is underway in earnest for Donnie Wahlberg’s Blue Bloods offshoot, Boston Blue – and a source says the actor is urging bosses to find some way to write his old costar and TV mentor Tom Selleck into the script.

“Donnie is an old-school loyal guy, he’s going to fight for Tom to get a piece of the action. He and Tom are still very close, they talk all the time and Donnie is well aware that Tom was not happy about Blue Bloods getting canceled,” an insider exclusively tells Closer. “Tom isn’t leaning on him or demanding anything of him, he’s got a movie in the works and is way too proud to beg. But Donnie wants to do this for him, not only because it’s the right thing to do, but also because he loves working with Tom.”

Blue Bloods aired its series finale in December 2024. Months later, after fan speculation and efforts to try and save the show, it was announced that Donnie, 55, would be leading an offshoot titled Boston Blue.

Along with Donnie, Sonequa Martin-Green, Ernie Hudson and Maggie Lawson have joined the cast of the upcoming CBS series, which is set to air this fall. Fans are still curious if Tom, 80, will be making a cameo as Frank Reagan in the show alongside his onscreen son as he takes a position with Boston PD. Per Tom’s IMDb, the TV veteran is currently working on an untitled Jesse Stone project amid the Boston Blue chatter.

“They have such a special bond, it really is a family feeling and Donnie misses seeing him,” the source adds. “He is feeling confident he can make it happen because the fans would love it as well. Even if Tom isn’t a full-time character, he can at least pop in and out for regular cameos, that would probably be a good fit for him at this point in life anyway.”

A separate insider previously said that Tom was interested in making an appearance on Boston Blue.

“Tom’s been pretty vocal when it comes to his feelings about the network ending Blue Bloods,” the second source told Closer in February. “He did not want to say goodbye to that role, so naturally he’s very open to coming back and doing cameos on Donnie’s show.”

The second source said that Donnie and Tom have been friends for more than a decade and still have a tight bond despite Blue Bloods ending.

“They are still very close, over the nearly 15 years they worked together they developed such a fantastic relationship,” the source added. “They’re genuine friends, in a lot of ways they grew to be like family, that’s how bonded they were.”

“They both got emotional filming their last dinner scene on Blue Bloods because it was the last, but now that this series is happening, they may get to do another,” the second source continued. “It’s set in Boston so it won’t be a regular family dinner thing like on the last show but there’s the potential and Tom would be all for doing it.”