The 30-year-old centre, who won the last of his nine England caps in the 2014 Four Nations Series, was ignored for the mid-season international against Samoa as coach Wayne Bennett restricted himself to just three players per club.
But Shenton remains in Bennett's 30-strong elite training squad, alongside Tigers team-mates Zak Hardaker, Luke Gale and Mike McMeeken, and his club coach Daryl Powell believes he should be a strong contender for the end-of-year World Cup.
Shenton's outstanding form has been pivotal to Castleford's sensational start to the season while his sublime handling has been key to winger Greg Eden topping the scoring chart with 21 tries in 15 appearances.
"I'm pleased with my form," Shenton said. "I've just got to keep playing well and stay consistent. There's some quality centres out there at the moment playing well.
"Of course I'm ambitious to play for England but my focus is clearly on Castleford.
. @SuperLeague returns to the Jungle on Friday and the boss has named his team. Book your tickets here https://t.co/AGfsd2jy59 #pontcashour pic.twitter.com/k8rkJ3q2ie
— Castleford Tigers (@CTRLFC) May 24, 2017
"I'm really enjoying my rugby, I love playing in this team and having people inside me like Luke Gale, Zak (Hardaker) and Jesse (Sene-Lefao), and the guy outside me is sensational as well.
"The way he has improved since we got him in the off season to now, with his timing, his ability to finish tries, he's worked so hard on that stuff that people don't see."
Eden, who is in his second spell with his home-town club following stints with Huddersfield Giants, Hull KR and Brisbane Broncos, is halfway to matching Denny Solomona's club-record try haul of 42 in 2016 and admits he has his sights set on playing for England.
"I'd like to think so," said Eden, who will make his 100th career appearance when Castleford host Widnes Vikings on Friday. "There's plenty of quality wingers in the Super League so I think there will be a fair few people fighting for the same spot."
Castleford, beaten just three times in the first half of the regular season, have a chance to consolidate top spot over the Spring Bank Holiday weekend when they play the bottom two teams.
It's a big weekend for our boys with 2 games Fri and Mon, starting with @WidnesRL here at the Jungle tomorrow night. Will you be here? pic.twitter.com/WobSjzyDA9
— Castleford Tigers (@CTRLFC) May 25, 2017
Widnes visit the Mend-a-Hose Jungle in a top-versus-bottom clash on Friday night, while Shenton takes his team to 11th-placed Leigh Centurions on Monday.
"We've given ourselves a fantastic opportunity and, being a leader in this team, the focus is making sure we don't slip," Shenton said.
"We've made a great start to the season and we don't want to let that go. We're not going to write them off. Widnes are battling for survival and we know how dangerous that makes them."
Widnes coach Denis Betts, who is prevented from playing new signing Rangi Chase against his parent club, is acutely aware of the size of his team's task and of the dangerous players they must close down.
"They are far and away the best team in the competition at the moment," Betts said. "Daryl has got them pretty switched on and he won't allow complacency to creep in."
WATCH: The Vikings won away at @CTRLFC in 2016 with a 38-28 win. Watch the highlights here, with tickets still available for Friday's game. pic.twitter.com/9oA2rjplBI
— Widnes Vikings (@WidnesRL) May 24, 2017
Betts, who is an England assistant coach, says he has recommended a fifth Castleford player to Bennett for the World Cup.
"One player who has been absolutely outstanding this year is Paul McShane, who has got to be in contention for international recognition at the end of the year," he said.
"His form has been outstanding all year and I spoke to Wayne Bennett before the international. He's on the radar, he's playing out of his skin."
In Friday's other fixtures, second-placed Salford Red Devils take on Catalans Dragons, the only team to beat them in their last 11 matches, Leeds Rhinos host Warrington Wolves, Huddersfield go to Wakefield Trinity and Hull FC are at home to Leigh.
