Wanganui Rugby Union club liaison officer Paul Kenny said Serawalu had verbally committed to Wanganui, although the word was that Manawatu thought he had verbally committed to them also.
"We are reluctant to release him because he has played rugby here in Wanganui all season - we'll see what happens," Kenny said.
Serawalu scored the match-winning try for Ngamatapouri in the club sevens final on Saturday.
The squad will train under coach Tom Wells at Cooks Gardens tomorrow at 6.30pm and then Monday and Thursday next week in preparation for the team's first assignment against the Heartland Sevens at Te Kuiti on November 21 and the Central Sevens in Levin on December 12.
-The full 2015 Initial Training Squad for Wanganui Men's Sevens: Ace Malo, Apenisa Ratugoleanavanua, Ben Whale, Bobo Ulukuta, Bryn Hudson, Dane Whale, Isireli Baleitavuki, Jaye Flaws, Kameli Kuruyabaki, Kieran Hussey, Patrick Hiscox, Samu Kubunavanua, Te Tua Kemp, Timoci Serawalu, Tom Symes, Tremaine Gilbert, Trinity Spooner-Neera, Tyler Rogers-Holden.
Coach: Tom Wells.
Manager: Gareth Hagan