Ferkranus joined the LA Galaxy academy in 2017, at the age of 14. In July 2020, he made his professional debut for the Galaxy's USL Championship affiliate, LA Galaxy II, coming on as an 81st-minute substitute for Jesús Vázquez in a 4–0 defeat to Phoenix Rising.[2] After making just five appearances throughout the shortened 2020 season, Ferkranus became a regular for the team in 2021, tallying 26 appearances, 16 of which were starts. Ankle and groin injuries ultimately limited his minutes in 2022,[3] and he would make just four competitive appearances for the club over the course of the year.
In January 2021, Ferkranus was signed to a first-team contract with LA Galaxy.[4][5] However, Ferkranus did not make a first team appearance before departing the club in June 2024.[6]
Ferkranus signed two year contract with the A-League side Brisbane Roar. As Marcus's mother was born in Sydney, he will not take up an international visa spot.[8]