CARLSBAD, San Diego County — If the A’s drastically improve their rotation and make another playoff run in 2019, they’ll do it with dwindling assistance from Major League Baseball.

Revenue sharing, which for years handsomely benefited the A’s, is incrementally being phased out, and the team will receive its final installment next season.

“It means the ballpark conversation becomes that much more urgent,” said general manager David Forst at the GM meetings, referring to the team’s quest for a new stadium and team president Dave Kaval’s intention to produce an economic deal for either the Howard Terminal or Coliseum site by the end of the year.

The collective bargaining agreement called for Oakland’s share of revenue sharing to be cut to 75 percent in 2017 and 50 percent this year. Next year, the A’s will get 25 percent of a sum that at one time was believed to exceed $40 million.

Then it’s gone.

The A’s are sticking with their plan to increase the payroll, which was lowest in the majors at the start of last season. Forst and executive vice president Billy Beane met with owner John Fisher last week to discuss spending parameters.

“We didn’t leave with a number I can report to you,” Forst said. “John has been pretty consistent in being open to what we want to do so I think we feel we have some flexibility.”

Once it was evident the A’s could be contenders over the summer, they made several in-season acquisitions to beef up their pitching staff and escalate the payroll.

“We’ve got a little more payroll (next) year than in the past,” Forst said, “but I don’t think we’re going to shock anyone with huge deals.”

In other words, no Patrick Corbin or Dallas Keuchel. Those are the top free-agent starters, both of whom will command more than the A’s are willing to pay. Among the next tier: Hyun-Jin Ryu, J.A. Happ, Nathan Eovaldi, Charlie Morton, Gio Gonzalez and Matt Harvey.

The Yankees re-signed CC Sabathia for $8 million and aggressively are shopping former A’s starter Sonny Gray, though their asking price is keeping teams at length.

The A’s have several free-agent starters including Edwin Jackson, Trevor Cahill and Brett Anderson, and Mike Fiers is arbitration-eligible.

“We need to find starting pitchers, and some of those will have to come from outside the organization,” Forst said. “We’re reaching out, but we never jump out and set the market or necessarily play at the top of the market.”

Forst said a goal is to re-sign some of the team’s free agents. Second baseman Jed Lowrie and catcher Jonathan Lucroy have hit the open market, so the A’s need to prepare for a Plan B at those positions. Second base isn’t as pressing with prospect Franklin Barreto in the wings.

Because Lowrie’s agent, Brodie Van Wagenen, is now the Mets’ GM, Lowrie switched agents and is now represented by Casey Close, who’s Lucroy’s agent.

“With Franklin as an option, we do feel you can plug him in and let him play that spot,” Forst said. “Behind the plate with (prospect Sean) Murphy, we probably think we’re a little further away. ... You need to have two (catchers) there for Opening Day so it’s a little more urgent than the second-base situation.”

John Shea is The San Francisco Chronicle’s national baseball writer. Email: jshea@sfchronicle.com Twitter: @JohnSheaHey