In his Sophomore season, Guenther posted a 3–5 record, 4.62 ERA, and a 1.369 WHIP with 11 starts and 15 total appearances in 2016.

In three starts and four total games with the GCL Marlins, Guenther only allowed one run, five hits, and eleven strikeouts in 11 innings.

Early struggles with the Hammerheads had Guenther demoted to the Greensboro Grasshoppers of the Single A South Atlantic League.

To begin the 2021 season, Guenther was assigned to the Pensacola Blue Wahoos of Double-A South.

[12] Guenther began the 2024 campaign with Toledo, recording a 3.86 ERA with 46 strikeouts and 3 saves across 44+1⁄3 innings pitched.

[13] He made his season debut later that day against the Kansas City Royals, coming in with two outs in the 8th inning in relief of Brenan Hanifee.