Brendan Donovan’s return is starting to feel a little more real. The Mariners have not unraveled without him. J.P. Crawford has done more than simply keep the leadoff spot warm, and Seattle’s lineup has found ways to function while Donovan has been out. But there is still a difference between patching around an absence and getting one of your more useful bats back into the mix. Donovan took that first visible step with Double-A Arkansas, opening his rehab assignment by going 1-for-3 with an RBI and two walks as the Travelers’ designated hitter. That is about as Donovan-coded as a rehab debut can get: one hit, multiple trips to first base, and enough zone control to remind the Mariners why they miss that skill set. He has been out since suffering a left groin muscle strain on April 17, an injury that landed him on the 10-day injured list and drew a little more attention because of its possible connection to his October 2025 sports hernia surgery. Seattle needed him to build back properly.…