Easter Sunday brought some much-needed good news for the Mariners’ beleaguered rotation: Hisashi Iwakuma and Taijuan Walker could be ready to reclaim their roles by the time the club heads back on the road. Note the qualifier: “Could.” Iwakuma threw a bullpen workout prior to Sunday’s game at Marlins Park as the final test for the strained ligament in his middle finger prior to beginning a rehab assignment Tuesday at Triple-A Tacoma. Plans call for Iwakuma to throw 45-50 pitches in his first outing, and then push to 70 pitches by next weekend. Barring a setback, he should return to the Mariners during a 10-game trip that starts April 29 in New York. Walker was scratched from a planned rehab start last Tuesday at Tacoma because of shoulder soreness, which previously plagued him in spring training. But club officials say he responded well over the last few days. Walker is tentatively scheduled to be examined Wednesday by Dr. Edward Khalfayan, the club’s medical director, and could be playing catch by the end of the week. That could position Walker for a swift comeback because he built endurance during two previous rehab starts. He threw 91 pitches on April 9 in a 10-strikeout performance at Double-A Jackson.