Key centrists have initial concerns about the cuts to Medicaid in a GOP healthcare reform bill.

Sens. Dean Heller, R-Nev., and Susan Collins, R-Maine, said in separate statements they have some early problems with the discussion draft unveiled by Senate leadership Thursday morning.

"At first glance, I have serious concerns about the bill's impact on Nevadans who depend on Medicaid," said Heller, who is up for re-election next year and faces a tough race.

Collins, who has expressed reservations on several parts of the bill in recent weeks, also has a "number of concerns," according to a statement.

The draft had some wins for centrists, but they were pushing for more time to phase out Obamacare's Medicaid expansion.

The draft ends the expansion in 2020 and phases it out over three years. Centrists had pushed for seven years but were rebuffed.

Collins added she wants to see what the Congressional Budget Office thinks about the draft's impact on insurance coverage and spending. A score on the bill is expected early next week.

Senate Majority Leader Mitch McConnell can only afford two Republican defections and get the bill passed.

Several senators said informal talks are still ongoing and the bill could change before a planned vote next week.