Having had an unsuccessful trial with Partick Thistle as a teenager, Shearer began his career as a striker at Scottish Highland Football League club, Clachnacuddin F.C.
However, early in the afternoon of the game, the Clachnacuddin chairman received a telephone call from Aberdeen to inform him that the reserve fixture that evening had been cancelled.
He left at the end of the 1985–86 season after appearing in only two League games in his three-year spell at the London club, scoring one goal, although he stated he learned a lot during his time at Stamford Bridge.
Although officially signed due to an injury to Mike Newell (who coincidentally also later played for Aberdeen), it has been suggested that Rovers only purchased Shearer to weaken Swindon's team in their league battle.
In November 1995, Shearer won the Scottish League Cup with the club, scoring the second goal in the 2–0 win over Dundee at Hampden Park.
In 1997, at the age of 35, he returned to his native Highlands to join Inverness Caledonian Thistle, where he played for two and a half seasons, making 55 league appearances and scoring 17 goals.
[5] In season 1999–00 he began to concentrate more on coaching than playing, and was in the dugout when Caley Thistle famously beat Celtic 3–1 in the Scottish Cup.
However, this did not prove to be a happy return to Pittodrie for Shearer, as Aberdeen struggled in the SPL and were put out of the Scottish Cup at the fourth-round stage by Livingston.
He was sacked in April 2008, after a disappointing home defeat to Cove Rangers effectively ended Buckie's hopes of winning the Highland League championship.
Shearer and fellow coach, Scott Kellacher, were put in temporary charge of the first-team after manager Terry Butcher moved to Hibernian in November 2013.