In his fourteen-year career he caught 650 passes for a total of 10,320 yards and 63 touchdowns. He surpassed 1,000 yards receiving 4 times: 1963 to 1965 and 1969, his most prolific year being 1965 with 81 receptions for 1,286 yards. His best TD totals were 1962 and 1969 with 11, his best point totals 1969 with 148 points and 1962 with 129. He was replaced as the Tiger Cat place kicker by Ian Sunter after the 1971 season, hitting only 11 of 27 field goal attempts. He also played some defense in his first two years, intercepting 3 balls in 1959 and 1 in 1960.

Coffey was a member of two Grey Cup winning teams, in 1967 and 1972, both with Hamilton against the Saskatchewan Roughriders, especially during the 1967 season, catching 42 passes for 683 yards (16.3 yards/catch) and 5 touchdowns and hitting 18 of 27 field goal attempts for a total of 107 points. In the 55th Grey Cup (1967) game, he scored 3 points as a kicker (2 converts and 1 rouge after a missed field goal). In the 1967-1972 span with Hamilton, he scored 603 points, third on their all-time list, see Hamilton Tiger-Cats all-time records and statistics.

In 1968 Coffey's helmet was stolen from a pool hall. 48 years later in November, 2015 Coffey is reunited with his stolen helmet.