Last was Lee Radford’s right-hand man at Hull, taking charge on an interim basis after the coach was sacked early in 2020.
He was on Wakefield’s coaching staff last year and moved to Castleford when Radford took charge there last autumn.
“I’m really really enjoying it,” Last said of his new job.
“It was good to reacquaint with Lee after a couple of years apart.
“It’s a great opportunity, a big club and we’ve fallen on to a very good group of players.
“We’ve made some additions who are hoping to take us to that next level, but we have inherited a good group of players and we are looking forward to it.”
Tigers’ new-look squad made a solid start last week when they opened their pre-season campaign with a 32-10 win at York City Knights.
Sunday's game at League One Doncaster is their only other fixture before the Betfred Super League round one visit of Salford Red Devils on Friday, February 11.
Last said: “What we wanted last week was a good hit-out against strong opposition, to come out unscathed and for the guys to get some opportunities to build combinations under game pressure.
“We got that and we got an opportunity to look at some of the younger boys in unfamiliar positions.
“I thought we came out of it reasonably well and we’ll be looking to do the same against Doncaster.”
Tigers will again field a strong squad and Last added: “We want to give some of the established players in the team another run.
“It is good for their confidence and good for combinations, against unfamiliar opponents.
“It’s likely to be a strong team again for the first 50-60 minutes and we might have a look at some of the younger guys after that.”
Castleford Tigers (at Doncaster): from Sutcliffe, Martin, Faraimo, Robb, Blair, Smith, Richardson, Olpherts, Collins, Griffin, Mamo, Trueman, Qareqare, Westerman, Vasuitoga, Edwards, Fonua, Massey, Evalds, Morley, Hall, Matagi, Hepi.
Kick-off: Sunday, 3pm.
Referee: James Jones (Bridgend).
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