Clinkscales played college football at the University of Tennessee, where he was a member of the 1985 "Sugar Vols" squad, and was a captain of the 1986 team.
He converted to wide receiver during his first year, deferring the quarterback position to highly talented fellow signee Tony Robinson.
[7] In spite of the stiff competition for playing time, Clinkscales caught 68 passes for 1,105 yards and 10 touchdowns during his college career.
In the Vols' 43–30 loss to Florida, Clinkscales made an athletic 48-yard touchdown catch in the 4th quarter to pull the team to within a score.
[16] He caught two short passes in Tennessee's 1986 Sugar Bowl victory,[12] including a key third-down conversion on the Vols' first scoring drive.
[20] In a key game against Ole Miss late in the season, Clinkscales caught 6 passes for 92 yards, including a 38-yard touchdown reception in the 4th quarter that gave the Vols the lead.
[23] One reason he was not selected earlier in the draft was his lack of speed, as his time of 4.55–4.65 seconds in the 40-yard dash was considered slow for an NFL receiver.
"[24] Steelers offensive coordinator Tom Moore noted that Clinkscales had "a tremendous amount of quickness and concentration and ball judgment.
"[24] Although Clinkscales performed well in the Steelers' 1987 training camp, he fell behind after suffering a leg injury, and was cut after the first preseason game.
Following an injury to veteran John Stallworth, Clinkscales received considerable playing time in the game against Cincinnati, catching 4 passes for 51 yards.
This move reunited Clinkscales with his old high school and college teammate, Raiders General Manager Reggie McKenzie.