After signing a 3-year agreement with the Alouettes, Muamba had a season that lived up to expectations in 2018. He was unanimously named the Alouettes most outstanding player, while he had a amazing season when he returned to Montreal. The linebacker played all regular season games and collected 108 defensive tackles, 5 quarterback sacks, 1 interception and 1 forced fumble.
He played 17 regular-season games, with 13 starts, at middle linebacker. He also had team-leading 82 defensive tackles and added 11 special-teams tackles, five knockdowns, three forced fumbles, two quarterback pressures, two interceptions and one tackle for loss. Muamba started both Eastern Semi-Final and Eastern Final, during when he had 15 defensive tackles, two special-teams tackles and one tackle for loss. He has been named 2017 Riders’ Most Outstanding Canadian.
In 2016, he attempted to return to the NFL by signing with the Dallas Cowboys and played the preseason games. Muamba was released in the final cuts on September 2. He then returned to the CFL again by signing with the Saskatchewan Roughriders.
Muamba played in 4 games for the Alouettes, contributing 14 tackles and 1 interception.
Muamba managed to join the 53-player squad of the Indianapolis Colts at the beginning of the 2014 season. Mainly used on special teams, he played 13 games and collected 6 defensive tackles. He was released before the beginning of the 2015 season.
He recorded 65 tackles and 3 sacks, adding another 20 tackles on special teams. Muamba built upon the strong 2012 season he had with an even better 2013 season. He set a new career high with 106 tackles (2nd most in the league), while also adding 1 quarterback sack, 1 interception, 1 fumble recovery and 1 defensive touchdown.
Muamba was the President’s Trophy winner last season, which is given annually to the top defensive player in the CIS. He leaves St. F-X as the school’s all-time leader in tackles with 149.5 and enjoyed a tremendous senior season which saw him finish second in the Atlantic University Sport Conference (AUS) and fourth in the country with 63.5 total tackles. He also ranked in the top ten in his conference with 11 tackles for losses and 3.5 sacks, while adding one interception, one forced fumble and one fumble recovery. Muamba's performance earned him All-Canadian status for the third straight season, including first-team nominations two years running. He participated in the CIS East West Bowl and was also the AUS nominee for the President’s Trophy in 2008.