The 51-year-old’s stock is already high for the way in which he has transformed the unfashionable West Yorkshire outfit into Super League pacesetters.
With their exciting brand of rugby, Castleford have thrilled crowds in 2017 and are on a seven-game winning run in their bid to lift a first-ever league title.
Current England coach Wayne Bennett is out of contract after this autumn’s World Cup, although the Australian is said to be in talks over a new deal.
However, regardless of when it occurs, Gill feels the former Leeds Rhinos chief must be next in line to take over the role.
“Daryl Powell, for me, has got to be the next England coach,” he told The Yorkshire Post.
“And I’d love to see him do it. Obviously, we’d still want him to honour his deal with Castleford – he’s signed here until the end of 2020 and I believe he wants to build something special with us.
“What he does after that only Daryl can say. But we’d support him working on a part-time basis if the RFL ever did ask about him.
“He’s probably the best coach in Super League at the moment.
“We always expected him to do well but we’re probably two years further on from where we expected to be and that’s testament to the work Daryl and his staff have done here.”
Powell, who played 33 Tests for Great Britain, arrived from Championship neighbours Featherstone Rovers during 2013.
He won Super League Coach of the Year in 2014 when Castleford also reached Wembley and Gill admitted: “Daryl has reinvented how we play and how games should be played.
“It’s blown teams away at times and you’d want to see it tried at international level. Are we happy competing with Australia at their game or do we go with our own brand with more ball movement?
“Daryl sees enough games and enough players, he knows how to bring the best out of them and give them confidence. He’d be ideal for the England job.”
Former Great Britain coach Brian Noble has already said Powell should be Lions chief in 2019 when Great Britain is revived for a tour Down Under in 2019.
Meanwhile, it was announced yesterday Powell’s assistant coaches Danny Orr and Ryan Sheridan - both former Great Britain internationals, too - have earned new Tigers deals until 2020 along with head of strength and conditioning Ben Cooper.
Gill said: “Danny, Ryan and Ben have been vitally important in the growth of our club and the development of our players in recent years, and their importance has been duly recognised not only at club level, but at international level too.”