Wilkinson, who has attracted interest from Spain, would need to accept a reduced role, with the club committed to giving Alex Pledger more game time, and a pay cut of "six or seven per cent" said Clarke.
He is presently playing in Puerto Rico and has said he couldn't play for a rival Australian club.
"There's a spot for him here if he wants it, provided he's happy with the role and the contract," Clarke said. "He loves it here and so does his family so it will come down to financials. We are pretty close to where we were last year but he will probably think there's room for an upgrade based on his results.
"We won't be able to compete with what he could potentially get in places like Spain or Italy. The decision for him will be about location, environment and reasonable money against bigger offers elsewhere."
Jackson harbours ambitions to return to the NBA but the club want him back and are willing to build a contract around that. They are in talks with his agent about Jackson returning but giving him until September 1 to find an NBA contract.
The final position after two imports and Henry are added is likely to be for a back-up guard. Final decisions on that position will be made after reviewing the free agents list and performances of local players in the New Zealand NBL but will also come down to what room the club have under the points rating - all players are given a points rating and clubs must fit 10 players under 70 points.
A large number of players were named on the free agents list but few fit what the Breakers are searching for.
"We have so many players signed it's not like we are out shopping for more," Clarke said. "We also have only seven points available for two players [including Henry]."
That means a local could be offered the final spot, with Clarke suggesting Josh Bloxham, Jarrod Kenny and Lindsay Tait were in the mix along with Corey Webster who will have served his one-year suspension for a drugs ban.
"There are some quality local players in the mix for the final roster position," Clarke said. "The final position will also be a points-based decision, depending on what we still have available for that spot once the other positions are confirmed."