Career
He played for Esbjerg fB from 2009 before signing with Ipswich Town in 2015. He is known for his long throws, and in Denmark his throws have been compared to Rory Delap. Esbjerg
In November 2009 he signed his first professional contract with Esbjerg, and following the winter break of the Danish Superliga, he made his professional debut in a 0–4 home loss against Randers Football Club, becoming the second youngest Esbjerg debutant ever second only to Andreas Sørensen who made his debut aged 16 years.
Following the departure of Kevin Conboy to Nippon Electric Corporation, Knudsen established himself as the first choice left back for the club
Ipswich Town
Knudsen signed for Ipswich Town on 31 July 2015 on a three-year deal.