Pops Mensah-Bonsu was ruled out of this autumn's EuroBasket finals when Great Britain's men named their squad.
NBA stars Luol Deng and Ben Gordon are in the party but Mensah-Bonsu, a key player in last year's qualifiers, will miss out after shoulder surgery.
The squad will prepare for five weeks before the EuroBasket finals start in Lithuania at the end of August.
"Now it's incumbent on our guys to arrive in peak shape to take GB to a new level," said coach Chris Finch.
Despite the loss of Mensah-Bonsu, the squad is probably the strongest yet assembled by Great Britain.
"Each summer one of our goals is to get our best talent together," said Finch. "We are constantly looking to work with younger players and continue to evaluate those who we see as real contenders to help us now and for years to come," he commented.
Mensah-Bonsu will still be rehabilitating from the shoulder injury he sustained while playing in France with Lyon-Villeurbanne last season.
"I'm very disappointed but I am also confident in the coaches and the players and I know that they will do the country proud," he said. "Although it will be difficult to watch, I will be supporting the team along the way, hoping and praying for the best."
Gordon has yet to make his debut for GB and the Malaga big-man pairing of Robert Archibald and highly-rated Joel Freeland are returning to the squad after missing last summer's matches.
With the exception of Mensah-Bonsu and Devan Bailey, all of last year's qualifying squad have been retained for this summer, which will see camp starting at the end of July and the first games, against Netherlands and Nigeria, taking place in Cobham on 7 and 9 August respectively.
GB will also take on Serbia, Croatia, Australia, China and France in a test event for the newly-opened Olympic basketball arena in the middle of August before directing their attention towards the EuroBasket finals, which start on 3 September in Panevezys.
GB face five teams in their group in the newly-expanded format, inclding hosts Lithuania, European champions Spain and World Championship runners-up Turkey.
Squad: Kieron Achara (Barcellona, ITA), Ogo Adegboye (St Bonaventure Uni, US), Robert Archibald, Joel Freeland (both Malaga, SPA), Eric Boateng (Austin, US), Flinder Boyd (AEK Athens, GRE), Matthew Bryan-Amaning (Washington Uni, US), Dan Clark (Estudiantes, SPA), Luol Deng (Chicago Bulls, US), Laurence Ekperigin (Biella, ITA), Ben Gordon (Detroit Pistons, US), Ashley Hamilton (Loyola Uni, US), James Jones, Nate Reinking, Andrew Sullivan (all Mersey, ENG), Mike Lenzly (Nymburk, CZE), Justin Robinson (Rider Uni, US).