Marlins option P Steve Cishek to Double-A to work on mechanics

The Marlins announced on Monday that they have optioned pitcher Steve Cishek to Double-A Jacksonville. 

Marlins manager Dan Jennings said Cishek has some issues to work on before getting back in the majors. 

"I don't think this will be a long term deal," Jennings said, via the Miami Herald. "It's about something mechanically that can be tweaked."

Cishek has appeared in 19 1/3 innings and has a 6.98 ERA. He's struggled throughout the season, having struck out only 17 batters while walking 10.