The former Rangers attacking midfielder believes that Kent could have done much more than he did for the Gers this past season.
Miller has added that the 23-year-old former Liverpool winger has much more to offer.
Miller told The Daily Record: “Ryan Kent is another one. I really believe that he can do so much more.
“It’s not having a go at him, but’s just that I believe he has so much to offer and it was so frustrating the way it didn’t work out last season.”
Kent spent the 2018-19 campaign on loan at Rangers from Premier League club Liverpool before making a permanent move last summer.
The former England Under-20 international winger scored six goals and provided six assists in 27 Scottish Premiership appearances for the Gers during his loan spell at Ibrox, according to Transfermarkt.co.uk.
Last season, the 23-year-old scored seven goals in 21 league matches, and scored one goal and provided two assists in seven Europa League games for Steven Gerrard’s side, according to Transfermarkt.co.uk.
With Rangers aiming to stop bitter Old Firm rivals Celtic from winning the Scottish Premiership title next season, Kent will have to step up his game and play an important role in that quest for the Ibrox club.