PORTLAND – It appears likely that the Boston Red Sox will move their Double-A affiliate to Portland, but it will be another week at the earliest before a decision is announced.

The Portland Sea Dogs’ contract with their major league affiliate, the Florida Marlins, ends after this season and has not been renewed. And the relationship between the Red Sox and their Eastern League team, the Trenton (N.J.) Thunder, appears all but over.

“Right now we’re kind of watchfully waiting,” said the Sea Dogs president, Charlie Eshbach. “You hear a lot of rumors. I’m just waiting to see what happens. No one will know anything until Aug. 20.”

Baseball officials aren’t allowed to talk about possible affiliation changes until Aug. 20, the first day teams can indicate they are looking for a change.

But recent comments by Red Sox owner John Henry and the Thunder president, Joe Finley, have left little doubt they are not renewing their contract.

Finley has expressed disappointment at the way the Red Sox have stocked Trenton’s roster. After recent trades and promotions, Trenton has slipped to 54-65, two games ahead of last-place Portland in the north division. Finley said he may have to look for another affiliation.

Henry, too, suggested that change is in the air.

Joseph Gray, Portland’s city manager, said Tuesday that the Sea Dogs and the city will split the $200,000 cost of upgrading the lights at Hadlock Field during the off-season. That move could also increase the team’s chances of aligning with the Red Sox.

Trenton and Portland both support their teams. The Sea Dogs are fourth in the league in attendance (5,544 average). Trenton is second (5,812). Being just a two-hour drive from Boston, Portland has a geographic advantage.

An affiliation with the Sea Dogs also would benefit from the huge reservoir of support for the Red Sox throughout Maine.

Speculation about a move began when the new Red Sox ownership took over in March. The group included two Mainers, former Sen. George Mitchell and Les Otten, founder of American Skiing Co. In addition, Henry, the former Marlins owner, and Tom Werner, a television producer, are friends of Dan Burke, owner of the Sea Dogs.

Some media reports have listed Portland and Manchester, N.H., as the top candidates for Boston’s Double-A team. But Manchester has no stadium and no financial plan to build one.