Gee was cut Monday, a day after he gave up eight runs and 11 hits in 3 2/3 innings against Atlanta in a spot start after being demoted to the bullpen.
General Manager Sandy Alderson said the Mets will try to trade Gee or push him through waivers for the purpose of sending him to triple-A Las Vegas.
Gee, 29, is being paid $5.3 million this year. He has a 5.90 earned-run average and sat out nearly a month because of a groin strain.
In his sixth big league season, Gee is 40-37 with a 4.03 ERA.
Blue Jays put Aaron Sanchez on the DL
The Toronto Blue Jays put right-hander Aaron Sanchez on the 15-day disabled list because of a mild lateral muscle strain.
Sanchez was sent to the Blue Jays' facility in Dunedin, Fla. He will have an MRI exam. The move is retroactive to June 6 so Sanchez is eligible to return June 21, the next time his spot in the rotation comes up.
Sanchez, 22, is 5-4 with a 3.55 ERA in his first 11 big league starts. He made his debut last season.
Miami Marlins right-hander Jose Fernandez says his target date to rejoin the rotation is July 2, about 13 1/2 months after he underwent elbow ligament-replacement surgery.
Fernandez, the National League rookie of the year in 2013, will make his third rehabilitation start Wednesday, this time with triple-A New Orleans. He made two starts for Class-A Jupiter.
The Marlins conclude a homestand July 2 when they face the San Francisco Giants.
Fernandez said his velocity reached 99 mph in his most recent outing, and he's happy with his slider. He said he just needs to get his pitch count up before returning to the majors.