The Australian, 32, has been in excellent form this season since switching from centre to back-row.
An NRL Grand Final winner with North Queensland Cowboys, Linnett is now in his third campaign at Hull College Craven Park.
He has scored eight Spoer League tries for the Robins this term, as part of their dynamic left-edge involving Man of Steel frontrunner Jordan Abdull, captain Shaun Kenny-Dowall and the competition's leading try-scorer Ryan Hall.
Coach Tony Smith said: "Kane is just a great professional.
"He trains hard, gets about his business, he turns up and does his work as best as he can.
"“He is another person (like Kenny-Dowall) that is very well respected in the group.
"He does most of his talking in the way he goes about his business. He’s an inspirational kind of man that is solid in everything that he does.
“He’s a massive contributor that gets through a huge workload and he’s always consistent about it.”
Smith is not surprised by the success of Linnett's switch to back-row this term where the Scotland international has excelled.
"He has been great there," said the coach.
"But I always thought he would be as good at second row as what he is at centre.
"He has handled it well and is easy either way, if I ask him to play centre he would, or on the right side he would.
"He’s just one of those ‘get on with it’ kind of players."
All of Abdull, Linnett, Kenny-Dowall and Hall are now signed up until at least the end of 2022 which is good news for Smith whose side have won three of their last four matches to move up to sixth.
Ahead of tomorrow night's game at Wigan Warriors, Smith admitted: “The left edge has performed well.
"They deserve extensions and recognition. I’m not a big one for turnover unless necessary.
"If people are doing their job and striving to get better, sometimes better isn’t out there in terms of replacement and it’s actually within us.
“If people are performing well and getting better then it’s much less of a risk than going out and trying to find someone new again, and often taking time to adapt to the culture and systems.
“I’d like to think that by keeping these boys together they are going to continue to improve not just for this year, but certainly for the next.
"Instead of trying to get things in place for next year, we already got a great platform for pre-season.”