The trade offers are starting to roll in for National League MVP Giancarlo Stanton.

The San Francisco Giants have made a proposal to the Miami Marlins for Stanton, and the Marlins expect to receive or have received bids from the St. Louis Cardinals and Boston Red Sox as well, according to major league sources.

Other, unidentified clubs also have told the Marlins they will submit offers for Stanton, but the process is just beginning, sources said. Marlins general manager Michael Hill said this week he wanted teams to inform him of the kind of proposals they were willing to make for Stanton before determining how he will proceed.

An initial offer does not necessarily indicate serious interest; some bidders might simply be trying to gauge the Marlins’ price. Any trade for Stanton is expected to include a combination of financial relief for the Marlins and prospects the team will use to rebuild. Under the sliding scale often used in such discussions, the more money the acquiring team absorbs, the lesser the cost in prospects.

Stanton, who turns 28 on Nov. 8, is guaranteed $295 million over the next 10 seasons, and his contract includes an opt-out after 2020 and a full no-trade clause, giving him the right to reject any deal. The All-Star right fielder’s preferred destinations are not known, and he has said he does not plan to reveal them.

“I know what I want to do. I need to know what you can do,” Hill said at the GM meetings in describing his approach to other clubs. “Until I know where you’re at on the contract, the money, all that stuff, I can’t engage.”

A trade, if completed, would reveal the Marlins’ true intentions—clearing as much of their financial obligation to Stanton as possible, effectively buying prospects by including significant cash in the deal, or a combination of both.

The Giants are willing to pick up a sizable amount of Stanton’s contract, one source said. Such a deal, however, would exacerbate the team’s luxury-tax concerns, likely resulting in the trade of at least one high-priced veteran, perhaps as part of a package going to the Marlins, perhaps to other clubs.