Real reason Justin Hartley's 'This Is Us' costars have not appeared in 'Tracker' revealed

Tracker fans who’ve seen Justin Hartley in This Is Us are always wishing his costars from the drama show would appear in the new show.

But there’s a reason his This Is Us siblings Sterling K. Brown and Chrissy Metz and parents Mandy Moore and Milo Ventimiglia haven’t made guest appearances in the show yet.

Tracker’s executive producer Elwood Reid explained the hold up, saying, "We discuss it] all the time. If I’m going to go with those kind of big names, I got to make sure I have a story."

"The show works because we’re with Colter so much and he’s just such an interesting actor that he’s able to carry that big narrative load," he added to Us Weekly.

"We’ve definitely talked about Sterling K. Brown, we’ve talked about Mandy Moore and we have talked about Milo Ventimiglia," he shared. "But until it’s really, really right — and matching the windows up in these people’s calendars is impossible."

"If I have the right story line, I will do it. But I’m always opposed to just do a cameo. We have to get a good emotional story out of it or a fun story line," Reid concluded.

Two of Hartley's This Is Us costars, namely, Jon Huertas and Jennifer Morrison have appeared in Tracker.

Tracker season 3 episodes drop every Sunday on CBS and Paramnout +.