However, it was towards the end of the campaign where he reverted to No 1 and Rankin – who scored 11 tries in 22 games in total – revealed head coach Daryl Powell sees him there again next season.
“Full-back’s my spot at the moment and I am enjoying it,” said the 27-year-old, who will spend another campaign at Wheldon Road following the swap deal with Joe Wardle.
“They’ve given me the role there at the moment and I’m looking forward to really nailing that down.
“We’ve got some competition for the spot there and there’s no doubt that’s the same across the team.
“But I played most of the back end of the year at full-back and really enjoyed playing there.
“I thought the team itself was really good at the back end of the year, too, so that helps my game as well.
“I’m looking forward to working with Daryl and Shez (Ryan Sheridan) and all the other boys, having that pre-season under my belt and going forward from there.”
Samoa international Peter Mata’utia was Castleford’s main No 1 last term but he showed his own versatility by playing at centre and also stand-off.
England Knights scrum-half Danny Richardson – one of the club’s big signings from St Helens – is likely to partner Great Britain tourist Jake Trueman in the halves this time around.
On training so far, former Hull FC star Rankin added: “We’ve had a pretty good start to pre-season.
“It’s been a bit different to what I’ve been used to in previous pre-seasons at other clubs; we’ve tried to get the ball in hand as quickly as possible and do all our conditioning work when it comes to under fatigue, playing games.
“The boys have trained really well and the new guys have settled in really well.
“Obviously with Danny (Richardson) coming in it’s going to make it an even better pairing that we’ve got with Truey at the moment as well so I’m really looking forward to it and working on those combinations.
“Having arrived in January this year as well, it’s good to now get a full pre-season in with Cas this time around.”
Tigers spent Saturday climbing The Yorkshire Three Peaks Challenge as part of their training regime and also to help raise money for local charity, The Prince of Wales Hospice.
They were still feeling the after-effects of the gruelling trek a few days later.
“I’m pretty sore and tired,” conceded Rankin.
“It was quite a day. I’m pretty lucky as I did it with Huddersfield last year so I knew what was coming.
“Myself and Daniel Smith are probably the only two players who had done the Three Peaks before but the rest were new to the experience and it didn’t disappoint, that’s for sure.
“The last time I did it, it was the middle of December and raining and not the best conditions.
“But the other day it was a quite still, sunny day so conditions-wise we couldn’t have asked for a better day to do it.
“The boys had a decent time and even though it was quite hard they definitely enjoyed themselves for the most part.
“At times, we were struggling to get through the walk but at the back of our minds it helped knowing it was all in aid of a good cause.”