What a missed opportunity though for him. He seemed to be heading for a Prem club, but maybe didn't do as well as expected at Blackburn. Now he's back where he started, at Gillingham. I'm surprised a bigger Lg One club didn't show an interest in him though.
I think injuries have knackered his career mate. edit. Just had a look at wiki, which says he’s had two cruciate injuries.
Great player if they can get him fit and injury free Missed over 2 years with 2 cruciate ligaments, one virtually straight after the other, and then more another 8 months with thigh problems, and then lots of little niggly injuries for a game or two Bet he's gutted, he's truly been ravaged by injury
https://www.gillinghamfootballclub.com/news/bradley-dack-rejoins-gills He did well at Blackburn. If he hadn't done both his cruciates he likely would have ended up a Premier League player. He's still young enough to get back up the leagues and going back to where he started is a good idea. No mention of contract length.