Bradley Dack made a low-key return for Gillingham on Tuesday night but manager Mark Bonner is expecting him to have a big impact. Dack made his first appearance since leaving the club for Blackburn Rovers in 2017, playing 45 minutes alongside Josh Andrews in attack against Peterborough United in the midweek EFL Trophy defeat. It’s step-by-step progress for Dack, 30, as he edges closer to full fitness. Bonner said: “He is really good and the more he gets involved and in the team, he’ll make others better, and he’ll raise standards. So that’s to come. “I think that’s just a natural thing for a r…