Keetley began his major junior career in 2003–04 with the Medicine Hat Tigers of the Western Hockey League. He initially began the season in the Alberta Midget Hockey League, but took over as the starting goalie for the Tigers during the 2004WHL playoffs, subsequently leading the club to a President's Cup championship. In Keetley's draft year, he led the WHL with a 1.66 goals against average and a.933 save percentage. He was then drafted in the fifth round of the 2005 NHL Entry Draft, 158th overall by the Calgary Flames. Keetley returned to the WHL for two more seasons, putting together his most accomplished major junior campaign in 2006–07. In the regular season, Keetley led the league with 42 wins and was named to the WHL East First All-Star Team. In the playoffs, Keetley won the airBC Trophy as playoff MVP, leading the Tigers to their second WHL championship in four years. Advancing to the 2007 Memorial Cup, Keetley won the Hap Emms Memorial Trophy as the tournament's outstanding goaltender and was named to the Memorial Cup All-Star Team as the Tigers fell to tournament hosts and WHL runners-up, the Vancouver Giants. During the Memorial Cup tournament, on May 22, 2007, the Flames signed Keetley to an entry-level contract. In 2007–08, Keetley was assigned by the Flames to their American Hockey League affiliate, the Quad City Flames. He was called up to play backup to Flames starter Miikka Kiprusoff on several occasions throughout the season. In a game against the Colorado Avalanche on November 5, 2007, Keetley made his NHL debut, replacing Kiprusoff with just under 10 minutes to go in the third period, making two saves. Keetley completed his rookie professional season with a 10-8 record with Quad Cityto go with a 2.33 goals against average and a.933 save percentage. To begin the 2008–09 season, Keetley was named AHLPlayer of the Week on October 27, 2008. On February 10, 2009, Keetley was reassigned to Calgary's ECHL affiliate in Las Vegas for seven games before returning to Quad City's roster. One year later, the Abbotsford Heat assigned Keetley to the Victoria Salmon Kings for conditioning purposes from November 10–17, 2009. During his brief three game stint with Victoria, Keetley would record two wins and two shutouts and was named the ECHL's Goaltender of the Week on November 17, 2009, before he returned to the Heat's lineup.