Metchie was drafted by the Stampeders in the third round, 25th overall, in the 2018 CFL Draft and signed with the team on May 14, 2018.[2] He began the 2018 season on the practice roster, but was soon elevated to the active roster and played in his first game on June 28, 2018, against the Ottawa Redblacks. He dressed in seven regular season games in his rookie season and recorded five special teams tackles.[3] He was on the practice roster during the playoffs when he shared in the Stampeders' 106th Grey Cup victory.
Following the off-season departure of starting safetyTunde Adeleke and the retirement of Adam Berger, Metchie became the Stampeders' starting safety for the 2019 season.[4] He recorded his first career CFL interception during the Labour Day Classic on September 2, 2019, against the Edmonton Eskimos.[5] He played and started in 17 regular season games for the team in 2019 where he had 48 defensive tackles, seven special teams tackles, and three interceptions.[6]
He signed a contract extension with the Stampeders on January 18, 2021.[6] He played in seven games in 2021 where he had 31 defensive tackles, one interception, and one forced fumble.[3]
Toronto Argonauts
On February 4, 2022, Metchie was traded to the Toronto Argonauts in exchange for Cameron Judge as both players had contracts expiring the following week.[7] He played in 17 regular season games where he had 72 defensive tackles and two interceptions.[8] He also played in both post-season games, including the 109th Grey Cup, where he recorded three defensive tackles as he won his second Grey Cup championship in the victory over the Winnipeg Blue Bombers.[3]
On February 3, 2023, it was announced that Metchie had signed a two-year contract extension with the Argonauts.[9] On June 25, 2023, he scored his first career touchdown when he intercepted Jarret Doege and returned the ball 15 yards for the score.[10] He played and started in all 18 regular season games where he matched his career-high of 72 defensive tackles and also had three pass knockdowns, two forced fumbles, one fumble recovery, and one interception for a touchdown.[3] He also played in the East Final where he had five defensive tackles and one pass knockdown in the loss to the Montreal Alouettes.[3]