Ever since Blue Bloods ended and Boston Blue emerged as its successor, one question has overshadowed almost every conversation surrounding the franchise:

Will Tom Selleck return as Frank Reagan?

For many viewers, Frank Reagan wasn’t just another character. He was the heart of Blue Bloods for fourteen seasons, serving as both New York City’s police commissioner and the moral center of the Reagan family. That is why his absence from Boston Blue has been felt so strongly by longtime fans.

Recent comments from those involved with the spin-off have only fueled speculation.

Donnie Wahlberg, who stars in Boston Blue as Danny Reagan, has repeatedly expressed his desire to reunite with Selleck on screen. In multiple interviews, Wahlberg has spoken warmly about their years working together and has made it clear that the door remains open for Frank Reagan to appear in the series. While he has stopped short of confirming anything, his enthusiasm has given fans plenty of reason to remain optimistic.

Meanwhile, producers behind Boston Blue have also acknowledged the enormous importance of Selleck to the franchise. According to showrunners, Frank Reagan’s presence still looms over the series even when he is not physically on screen. The character is frequently referenced, reminding viewers that Danny’s move to Boston does not mean he has left his family behind.

The situation becomes even more intriguing because Tom Selleck himself has never hidden his disappointment over the cancellation of Blue Bloods. Following the original series’ conclusion, the actor openly discussed how much the show meant to him and how strongly he believed there were still stories left to tell. Those remarks immediately sparked speculation that he might eventually revisit Frank Reagan if the right opportunity arose.

Industry observers note that bringing Frank into Boston Blue would instantly become one of the biggest television events of the season. The character remains enormously popular, and many fans consider him essential to the Reagan family dynamic. A reunion between Frank and Danny would undoubtedly generate headlines and likely attract millions of curious viewers.

At the same time, there are practical challenges. Selleck has spent years carrying the demanding workload of a network television lead. Since Blue Bloods ended, he has reportedly been enjoying a slower pace while focusing on family life and personal projects. Any return would likely need to fit around those priorities.

That hasn’t stopped fan theories from spreading online.

Some believe Frank could appear during a major Reagan family gathering. Others speculate that he could become involved in one of Danny’s most important investigations. A particularly popular theory suggests that Frank might appear in a recurring role rather than as a one-time guest star, allowing the series to maintain stronger ties to the original show.

Adding to the excitement is the fact that several other Blue Bloods veterans have already made the jump to Boston Blue. With familiar faces such as Bridget Moynahan and Len Cariou returning, fans naturally wonder whether Selleck’s turn is only a matter of time.

Of course, nothing has been officially announced. CBS has not confirmed any appearance by Tom Selleck, and the actor himself has not publicly committed to joining the spin-off.

Yet the conversation refuses to disappear.

In many ways, that reflects the unique place Frank Reagan holds within the franchise. Even after the end of Blue Bloods, audiences continue to view him as the figure who holds the Reagan family together. Whether offering advice around the dinner table, guiding Danny through a difficult case, or defending his principles as police commissioner, Frank became one of television’s most enduring patriarchs.

As Boston Blue moves toward its next season, one thing is certain: no potential guest appearance would generate more excitement than Tom Selleck stepping back into Frank Reagan’s shoes.

And until CBS finally gives a definitive answer, fans will continue hoping that the Reagan family reunion is only one episode away.