Brian Noble has announced his 24 man Great Britain squad for the Gillette Tri Nations. Andrew Farrell will continue to skipper the side, while there are call ups for eight uncapped players in a youthful looking squad.
Noble has selected Leeds' Matt Diskin and Danny McGuire, while Iestyn Harris also makes the cut just five months after returning from rugby union.
"Kevin and Paul were very, very close to selection," said Noble.
"There's been some really difficult decisions. I've spoken to them both, who have played a huge part in what we've done over the last few years, and it's important they understand and know they're not thrown out.
"Form is very important and we are conscious about not having people around because they are a good name. We need people who can contribute throughout the series.
"The selection process is pretty meticulous. We've met every week and I think we've managed to come up with the right formula."
Despite Sinfield being left out, Leeds have a strong representation in the squad with Diskin and Maguire joined by team-mates Ryan Bailey, Keith Senior, Chev Walker and Danny Ward.
Diskin has played his way into the squad after making a massive contribution to Leeds' first title in 32 years, while McGuire's astonishing total of 39 tries made him a certainty for selection.
Noble, who coaches Bradford in Super League, also left out Bulls scrum-half Paul Deacon.
Sean Long, who only returned at the end of the season after being suspended for his part in a betting scandal, is the only specialist scrum-half in the squad.
Long has played just two games since his return and underwent ankle surgery two weeks ago, while Wigan winger Brian Carney has played for just 10 minutes in the last six weeks because of a hamstring injury. "Sean is running again and the medical prognosis for him is very encouraging and Brian is also in full training," said Noble.
Martin Gleeson, who was also banned for his involvement in the betting scandal, is included despite not played since June.
Gleeson's four-month ban ended last weekend but has been training flat out with new club Warrington.
Britain are likely to bring in one more player - to take them up to a 25-man squad - from the 20-man England squad for the European nations squad.
"We need to give Karl Harrison (England coach) and his team the incentive to perhaps find one more player to bring us into line with Australia and New Zealand," said Noble.
"We've got that facility to bring in someone extra and we probably will."