It is barely six weeks since Hull unexpectedly sold Watts to their Yorkshire rivals, FC questioning the 27-year-old’s off-field discipline as one of the reasons for his departure.
But Watts, also sent off four times in just 11 months for the Black and Whites, has instantly settled in with his hometown club ahead of the Super League meeting at KCOM Stadium.
It will be interesting to see how the sometimes volatile player, who won back-to-back Challenge Cups with Lee Radford’s side over the last two years, will handle the pressure that will certainly come his way.
Asked if he had any advice for Watts with Hull likely to try and wind him up, Australian forward Millington said: “Hopefully he knows what to do.
“But you’re right, I think they will have a dig at him because he’s been in little bits of trouble before, which is part of the reason why he left initially I guess.
“It’s definitely going to be a tactic of theirs to try and get him off the pitch because he’s such a good player.
“But he’ll know in the back of his mind that they’re going to do that and he’s just got to keep his cool and not play their games.”
Watts will be urged to stick to doing what he does best – ripping into sides down the middle and hurting them with his offload game.
Castleford are blessed, in that sense, in having two creative front-rows given Millington is similarly adept at finding a pass in such a manner.
The 31-year-old is enjoying playing alongside Watts as last season’s beaten Grand Finalists seek a ninth win of the campaign.
Millington explained: “He’s settled in really quickly. We were sitting in video the other day and I was asking him if it feels strange preparing to play his old side and he said ‘not really.’
“It feels like he’s been here for quite a while and he’s put that past behind him and moved on already.
“He’s moved forward and is committed to doing his best for us, but I’m sure in the back of his mind it will be a big occasion for him to go and steal two points over there.”
Hull will draw level with Castleford – fourth heading into this round – if they win but they have played two more games than Daryl Powell’s side.
The East Yorkshire club lost at bottom-placed Catalans Dragons a week ago, a mark of their inconsistent start.
“We’ve been pretty similar,” insisted Millington.
“We’ve been winning games but we’ve not hit our straps yet.
“Hull’s always a tough place to go; we went there last year when we were playing good stuff, Wattsy actually got sent off but they beat us with 12 men,” Millington said.
“It’s a tough crowd to play in front of. I assume it’ll be a cracking atmosphere and we have to stick to our game-plan to ensure we come out of there with the two points.”
That gameplan will revolve around playing without either of their first-choice half-backs.
Benny Roberts was missing from last week’s win over Wakefield Trinity but England scrum-half Luke Gale fractured his kneecap in that game meaning the Man of Steel will now miss three months of action.
Such is Millington’s handling quality, he has filled in at half-back previously with Castleford but today Powell is more likely to shift hooker Paul McShane there or maybe give scrum-half Cory Aston his Super League debut.
Aston, 23, joined from Leeds Rhinos over the winter having not featured with them and has been playing on loan with Sheffield Eagles – his original club – in the Championship of late.
It would be fitting if he did at last make his bow this evening at the end of a week where Sheffield celebrated the 20th anniversary of their famous Challenge Cup final victory over Wigan Warriors.
Aston’s dad Mark won the Lance Todd Trophy that day as the Eagles pulled off the biggest shock in the competition’s history.