The Mariners announced Tuesday that outfielder Mac Williamson has been designated for assignment. His roster spot will go to utilityman Kristopher Negron, whose contract has been selected from Triple-A Tacoma. Seattle also recalled right-hander Erik Swanson from Tacoma to fill a vacant spot on its active roster.

Williamson, 28, was once viewed as a potential long-term option with the Giants but has yet to replicate his solid Triple-A production at the MLB level. Seattle gave him a slightly longer look than San Francisco did in 2019, but his results with both clubs were poor. In a combined 144 trips to the plate this year, Williamson has slashed an underwhelming .156/.250/.258 while striking out at a 30.6 percent pace. He does have some pop in his bat, evidenced by a lifetime .266/.344/.488 line in parts of five Triple-A seasons.

Williamson is out of minor league options, so any club that acquires him would have to carry him on its MLB roster. The Mariners will have a week to trade him, release him or attempt to pass him through outright waivers. If they go the latter route and he clears, Williamson could still elect free agency due to the fact that he’s already been outrighted off a 40-man roster once in his career.