Toronto Blue Jays catcher Reese McGuire -- a former MLB first-round pick -- was arrested last week after cops say he was caught exposing his penis in a Florida parking lot.
The Pinellas County Sheriff's Office tells TMZ Sports ... deputies were called to a public parking lot in Dunedin, Fla. on Friday after a man was seen inside of an SUV exposing himself.
FYI, Dunedin is the spring training home of the Toronto Blue Jays -- and pitchers and catchers were expected to report to camp today.
Cops say when they arrived .