Devon Conway has been omitted from new Black Caps head coach Rob Walter's first squad to play a Twenty20 tri-series against hosts Zimbabwe and South Africa next month. The veteran batsman is one of several leading players who have turned down central contacts with New Zealand Cricket to play in professional T20 leagues overseas. Conway last played for New Zealand in June last year, in their last group match at the T20 World Cup. Former captain Kane Williamson made himself unavailable while playing for Middlesex in England's county championship. Auckland batter Bevon Jacobs is the only uncapped player in the 15-man squad named by Walter on Friday. The 23-year-old Jacobs was a member of the New Zealand squad that played against Sri Lanka in December but did not play a game. Fast bowler Adam Milne has been recalled for the first time since November after performing well in Major League Cricket in the United States. Batters Finn Allen and Tim Seifert also return to the squad which will be captained by Mitchell Santner. Allen recently hit a world-record 19 sixes in an innings of 151 for the San Francisco Unicorns in Major League Cricket. "We've got a really strong squad for this tour and I'm looking forward to getting the team together and getting into the work," Walter said. "We've got some good experience in the side and it's nice to be able to welcome back a few of the players who missed the March series against Pakistan because of the Indian Premier League."