This piece is a short primer on Oregon State's crucially important baseball game tonight against the University of Portland. True freshman Trey Morris - a reliable weekday starter - earned promotion to pitching coach Rich Dorman's weekend rotation following Dax Whitney's UCL injury . In his stead, the Beavers are expected to lean on 6'0" junior righty Connor Mendez. Mendez transferred to Oregon State last summer from nearby Linn Benton Community College, a juco program managed by former Beaver player & coach Andy Peterson . At Linn Benton, Mendez pitched 78 innings across 12 games, with a white hot 0.69 earned run average. This season in Corvallis has been a much tougher challenge: across 19 and 2/3 innings, the junior has allowed 22 hits, 10 walks, 4 homers, and 20 earned runs. If he starts tonight, it will be his third meeting with Portland. On March 17th, Mendez threw 3 and 1/3 innings against the Pilots in an upset loss. A week ago, he faced Portland for 4 innings in a 6-4 win.…