The Red Sox designated Harris for assignment Tuesday.
Harris was acquired from the A's in late June and was up with the Red Sox for a couple days just before the All-Star break, going 0-for-2 in one game. The 28-year-old hasn't quite got on track with his new organization with a .711 OPS in 34 contests at Triple-A Worcester, which is a far cry from the .978 OPS he had at Triple-A for the Athletics.