The colourful Australian half-back has always been talented. That is not questioned.
Getting the best out of his gifts on a consistent basis has sometimes been a struggle for coaches but Lee Radford is certainly managing to do that now.
Although scrum-half Marc Sneyd took the man-of-the-match award for his brilliant game management in the 43-24 Challenge Cup semi-final win over Leeds Rhinos, and immense prop Liam Watts cannot have been far behind with his towering performance, few would have argued if Kelly had got the nod either.
Having missed the last two games with a calf strain, it was imperative Hull had him back in their side for this crucial date on the calendar.
Quite simply, the 26-year-old turns a good side into a very good side and one which is capable of very special things.
It is why the Airlie Birds – playing as they did on Saturday – will be genuine challengers to runaway Super League leaders Castleford Tigers when it comes to the race for Old Trafford glory.
Last season, Hull missed that little bit of creative edge required to sustain a bid for silverware in both fronts; they had enough guts and wherewithal to beat Warrington Wolves at Wembley but it was clear they also needed another attacking option to consistently crack the very best of defences.
Kelly, who arrived from Hull KR under a cloud, is just the sort they required and, 18 tries and countless assists later, he is proving the point markedly.
On Saturday, it was his slight shimmy and dart for the line that saw him score to draw level at 6-6, an opportunist try no-one else in his side is likely to have been able to exploit.
He then showed great dexterity to take Sneyd’s deflected kick on the run and still find a pass out of the tackle for Chris Green to score and give them an 18-12 interval lead.
There was also a lovely deft pass that created space for Watts to crash over as the East Yorkshire club really turned the screw in that dominant second period when he also illustrated his dangeorous running ability, too.
Indeed, there was a collective groan from FC fans as he headed off in the final stages, rightly concerned that the former Gold Coast Titan had suffered an injury relapse that could threaten his place for Wembley.
“I got a bang in the chest and couldn’t really breathe for a minute so I didn’t want to be a burden in those last crucial moments,” explained Kelly when back on the Keepmoat Stadium pitch afterwards conducting interviews.
“Jake (Connor) was on the bench anyway. I think Shauly had just scored and I was celebrating while walking off!
“I was winded a bit but it was just a precaution. I had one earlier this year; I wore a sternum guard in a couple of games but I don’t like strapping that much. I didn’t fancy it this time.
“But it should be okay. Time will tell but it’s no biggie.”
Kelly revealed Radford gave “everyone a licence to run” against Leeds which goes against the coach’s natural gameplan but explains why they shifted the ball wide in the very first set.
The tactic undoubtedly worked and seemed to take Rhinos by surprise while it was ideal for a player of Kelly’s style. On that, he said: “It gives you a little boost of confidence in what you’re doing out on the field.
“Hearing that, everyone else got a boost, too, but I think the energy and the passion from all the boys that took the field here today was outstanding.
“Hats off to everyone in the team for that. I thought I took it a bit slow at first but there were a couple of opportunities where I did take the line on and created a couple of opportunities.
“But the boys around me, they just make it a whole lot easier to do my job.
“And I try to make it a lot easier for them.”
It is easy to see why Radford did not want to rush Kelly back into action.
He said: “I had a chance of playing against Huddersfield last week but I think Radders wanted to rest me.
“I don’t like being rested. It was his call. But it was obviously the right one.”
Furthermore, this semi-final victory was all the more enjoyable for Kelly given the last time he faced Leeds in the Challenge Cup was when Hull KR suffered that embarrassing record-breaking final defeat at their hands two years ago.
“It was 50-0 the last time I was at Wembley but the memories I made that week will last forever despite the result,” he insisted.
“That was the only downside. Hopefully, there’s a lot more memories to make again this time.
“Hopefully, we can come back with a better result this time, that’s all.”
With Kelly in the side, Hull’s chances of victory in both competitions are improved no end.