Fittingly, the former Leeds Rhinos and England captain entered retirement on a winning note as Yorkshire Carnegie defeated Doncaster Knights 14-11 on Sunday.
Ultimately, of course, it was not enough to see them through to the Championship play-off final against Bristol as they lost 44-34 on aggregate over two legs against their Broad Acres rivals.
After leading Rhinos to an historic treble, the legendary Sinfield switched codes last November on an 18-month deal – but announced a fortnight ago he would hang his boots up at the end of this current campaign.
After his final match in a 20- year career, he admitted: “It is strange and probably a bit surreal.
“I still feel like I’ll probably be back in training tomorrow.
“I don’t know but it will probably only sink in in four weeks time when the lads are back in for pre-season training.
“One thing I do know is it’s nice to finish fit and healthy; after 20 years of getting bashed, to come away from the end today and know my body is okay is a huge positive and I’ll now look forward to the rest of my life.
“I’m not too sure what the next step is but there’ll be a couple of holidays with the kids, I’ll spend some time at home and then think about what comes next.”
Carnegie had been 13 points adrift after the first leg but Sinfield said he still believed the squad had the potential to turn things around at a sun-kissed Castle Park.
“I think we made life tough last week with the score we had to chase but I felt we were capable,” said the 35-year-old, who won seven Super League titles with Rhinos.
“I felt we left points out there today but we got the win. It was important for us to do that but just not enough for us in the end.
“What a great day to play rugby and a great day to finish as well.
“It’s disappointing. I felt that we could have bridged the gap and got the victory and got the score we needed. I felt we could have pushed Bristol so it is disappointing but you have to move on haven’t you?”
Sinfield, the fourth highest point scorer in rugby league history, played 18 games for Carnegie, kicking 53 goals, and is glad he made the jump after more than 500 games with Rhinos.
“I’ve just really enjoyed it,” he said. “There’s moments in your life when you get opportunities to do things and you don’t always take them.
“This was something I felt I had to do. I’m really glad that I had the courage to step out of something that meant a great deal to me and try something new.
“I never thought I’d get to this stage, here with 40 new mates, and that’s a huge positive to come out of it; the friendships I’ve been able to gain on the back of a long rugby league career, to have those friendships now in rugby union, too, has been brilliant.
“I’d like to go on record and thank every single one of the lads.
“They have been fantastic as have the coaching staff who have put a lot of effort and work into me. To be able to have six really enjoyable months here thrown into a completely new challenge has been great. I know I came across for 18 months but I just felt this was the right time.”
For all Carnegie fell short in their attempt to win promotion this term, Sinfield remains confident they are moving in the right direction.
“They have got a great opportunity,” he added.
“The last few years they have been pretty close but with some of the additions in the coaching set-up – (Jersey forwards coach) Steve Boden coming in and obviously Jimmy Lowes who I’ve worked with a number of times in my career – that will add huge value to the team.
“We’ve signed some real quality players as well going forward and hopefully they’ll get a few more (sunny) days like this next year and the boys can open up, play some good running rugby.
“I’ll certainly be down supporting the team – not every week – but if we get days like this I’m sure I’ll be watching!
“I wish the lads all the best; the nucleus of the team is very, very strong and they have some great talent so onwards and upwards.”
Asked if he would instead soon be turning out for his former amateur club Waterhead in Oldham, Sinfield smiled: “No....no!
“I thought about setting the boots on fire – but not yet.”
England Under 20s captain Jack Walker has confirmed he is leaving Yorkshire Carnegie, with a Premiership move believed to be secured for the hooker.