With Negasonic Teenage Warhead by his side, Colossus was introduced in Deadpool to try to recruit Wade Wilson into the X-Men and teach him the morality of a traditional superhero.
Now that he and Deadpool are on good terms again, it would make sense to incorporate Colossus into X-Force, although I question if Wade would call the Russian powerhouse right away.
Following Vanessa’s death in Deadpool 2, Colossus brought Wade back to the X-Mansion after the Merc with the Mouth’s suicide attempt and offered him a spot on the team, which Wade accepted.
Disappointed in Wade’s actions, Colossus initially refused to help him, Cable and Domino stop Russell Collins and Juggernaut from killing the Essex House’s headmaster, but he later changed his mind and arrived at the scene with Negasonic and Yukio.