Flanker Jack Nelson-Murray and No8 Hannon Brighouse, who gained New Zealand Marist Sevens selection a fortnight ago, are the others.
Magpie Ellery Wilson and Algeria captain and former France Sevens rep, Boris Bouhraoua, rank ahead of Donaldson at the NOBM club which also has All Black halfback Brad Weber on its books.
However Super and international commitments are expected to take Weber out of the equation.
"I'll just work hard and see what I can achieve. You never know what opportunities will come up when injuries and departures come into play," Donaldson said.
Because of his cricket commitments which included captaining his school's 1st XI in the past, this is his first summer of sevens.
"It's pretty tough. But playing sevens and training for sevens will help me secure more game time with the Hawke's Bay Academy team and with my long-term goal of making the Magpies," Donaldson said.
Brighouse, Weber's brother Sam and 2015 Magpie Joseph Penitito were NOBM's key players at the New Zealand Marist Sevens and Donaldson said they should again lead by example in the club's quest to improve on last year's semifinal finish in Waipukurau tomorrow.
Donaldson's NOBM team will be among 20 in the men's grade where four Wellington clubs and four Manawatu teams will compete.
Defending Ian Baker Cup champions Havelock North won't have the services of Taranaki-based Trinity Spooner-Neera who scored five tries in last year's final.
The promising Tiaan Falcon, veteran Adam Bradey and Chaz Solomon are expected to be the kingpins for the villagers.
Last year's runners-up Hastings Rugby and Sports should again be competitive with the likes of Jayden Rihia who was also selected in the New Zealand Marist Sevens team.
Nine women's teams will chase the Jiangsu Jersey including last year's winners Feilding Old Boys Oroua and 2014 winners Avalon.
Hawke's Bay's best hopes in this grade will be Havelock North and MAC.
Petone will chase a third consecutive Angus Cup title in the 13-team colts grade.
Upper Hutt Rams and two teams from Palmerston North Boys' High School are other fancied starters from outside of the province.
Expect Havelock North to be among the best of the Bay's starters in this grade also.