SEATTLE — The Athletics acquired switch-hitting catcher Jonah Heim from the Atlanta Braves for cash on Monday night in a trade between first-place teams. Heim was designated for assignment by Atlanta following a big day at the plate Sunday to make room on the roster for catcher Sean Murphy, who came off the injured list Monday. Murphy made his season debut Monday night against the Seattle Mariners, starting behind the plate and batting seventh. Murphy, an All-Star in 2023 with the Braves and a Gold Glove winner two years earlier with the A’s, had been rehabbing in the minors following right hip surgery. The Athletics plan to move to Las Vegas in 2028, when they are scheduled to open play at a new ballpark on the Strip. Atlanta also has 2025 NL Rookie of the Year Drake Baldwin at catcher. Baldwin began the day batting .315 with eight homers, 29 RBIs and a .909 OPS for the NL East-leading Braves, who had the best record in the majors (25-10).…