But Millington enjoyed an impressive display, scoring a try and making plenty of metres for Daryl Powell’s side to leave them in positive mood ahead of Friday’s visit from Wigan Warriors.
“Before I came over here I was an out-and-out back-row,” he said, having joined Tigers from Canterbury Bulldogs in 2011.
“It’s only since I’ve been at Cas that I’ve gradually ended up at front-row and found my place there.
“It was funny as there were a few of us who had hamstring niggles beforehand coming into Sunday’s game.
“I was initially going to play back-row but the thought was I’d have to run a bit faster and they were trying to save my hamstring.
“They put Griff in there but we lost him so I ended up going there anyway.
“But the hammy came through okay which is great.
“And I’ve said before, when you get the opportunity to play a different position it’s always good fun - it’s something different to what you’re used to.”
Given Millington has also operated at stand-off in his time at Wheldon Road, this positional switch was relatively simple.
He may end up playing there again when Wigan - who defeated much-fancied Warrington Wolves last week - arrive on Friday.
“You always expect the same from Wigan,” said Millington.
“They’re tough in defence and always move the ball very well; they set the benchmark for teams that execute their gameplan.
“Your whole game has to be on against them as if you switch off in the slightest they will punish you.”
Castleford opened up a 22-4 interval lead against Toronto but Millington said: “We probably started a little bit erratic.
“The first game of the season, though, you always do come in with some nervous energy and there was a fair bit of hype around this game, too.
“But once we found our rhythm, we executed our gameplan and did a lot of little things right. That was reflected on the scoreboard.
“The middle part of the game was probably our best. It got scrappy towards the end which was disappointing but there’s always room for improvement and we’ll look to make that against Wigan.”