Rumball led Canada to a two-match series win over the U.S. to qualify for the second-tier under-20 competition, which runs May 12-24.
Canada, in a pool with Hong Kong, Namibia and Tonga, opens against Namibia on May 12. The other pool consists of Fiji, Georgia, Portugal and Uruguay.
Rumball and fellow back-rower Harjun Gill of Richmond, B.C., played in last year's tournament when Canada placed seventh.
"I think the reason this team has been successful thus far is because they're extremely hard-working, they're gritty and they're able to play any style of rugby," coach Jeff Williams said in a statement.
The tournament winner will be promoted to next year's World Rugby U20 Championship. Canada’s best finish in the U20 Trophy is second in 2013.
Phil Berna, UBC Thunderbirds, Vancouver; Brendan Blaikie, Queen's University/Markham Irish, Markham, Ont.; Luke Bradley, UVIC Vikes/Port Alberni Black Sheep, Port Alberni, B.C.; Owen Brombal, Guelph Redcoats, Guelph, Ont.; Andrew Coe, UBC Thunderbirds/Markham Irish, Markham, Ont.; Paul Cuilini, Aurora Barbarians, Vaughan, Ont,; Guiseppe du Toit, UVIC Vikes, Maple Ridge, B.C.; Patrick Finlay, Trinity University, Dublin, Ireland; Harjun Gill, UBC Thunderbirds/Richmond RFC, Richmond, B.C.; Dylan Horgan, UCC Rugby Club, Cork, Ireland; Daniel Joyce, Trinity University, Dublin, Ireland; Karsten Leitner, UBC Thunderbirds, Vancouver; Cali Martinez, UBC Thunderbirds, Vancouver; Ollie Nott, UVIC Vikes, Qualicum, B.C.; Reegan O'Gorman, Vancouver Rowing Club, Vancouver; Tony Pomroy, Baymen RFC, Conception Bay South, N.L.; Mitch Rothman, Vancouver Rowing Club, Vancouver; Lucas Rumball (capt.) Balmy Beach, Toronto; Mitch Santilli, Brantford Harlequins, Brantford, Ont.; Theo Sauder, UBC Thunderbirds, Vancouver; Emil Sehic, Fredericton Loyalists, Fredericton; John Shaw, Bytown Blues, Ottawa; Matt Tierney, Mississauga Blues, Oakville, Ont,; Adrian Wadden, Oakville Crusaders, Mississauga, Ont.; Bryce Worden, Burnaby Lake RFC/Belleisle RFC, Sussex, N.B.; Conor Young, Southern Districts RC, Sydney, Australia;