The East Yorkshire club today confirmed the signing of the Castleford Tigers centre/winger on a two-year deal.
Minikin, 24, had become a regular at Wheldon Road after joining from York City Knights in 2016, helping them win the League Leaders Shield and reach the Grand Final the following year.
But the Knaresborough-born player feels he can improve further under Australian Smith who has also taken Willie Poching on as his assistant coach with James Webster leaving.
“The deal to come here was done quite a while ago,” said Minkin.
“It was a relief when it all got sorted and I could then focus on finishing well with Castleford ahead of coming here for 2020.
“I met with Tony Smith for the first time only a couple of weeks ago.
“It was really interesting; I was a bit nervous beforehand, but he was a really nice guy and we chatted about all things pre-season.
“It has made me even more excited to join Rovers.
“I want to improve further on my game. I know the team has signed some great players next season that I can learn from and improve to be the best player that I can.
“I have watched Ethan Ryan, a fair bit, and he’s a really good finisher.
“Shaun Kenny-Dowall has played at the top level for New Zealand and in the NRL, and he is somebody that I can really learn from.”
Smith added: “Greg is a quality player; he is young, experienced, but still hungry to improve.
“He’s ambitious at the same time and I’m delighted to have him on board.
“He will add some of that enthusiasm and youthfulness but also experience of Super League.
“He’s played in big matches and played within a team that has been competing at the top end for the last few years.
“We need some of that knowledge and know-how from him to pass on to his fellow players.”