Gonzales (forearm) will throw off a mound Monday for the first time since landing on the injured list, Shannon Drayer of 710 ESPN Seattle reports.
The 29-year-old landed on the shelf with a mild forearm strain April 29 and has been throwing off flat ground, but Monday will be his first time throwing off a mound since suffering the injury. Gonzales was initially expected to face a short absence, but the left-hander likely will need some time to build his stamina back up after being limited for the past couple weeks.