He was loaned to Notts County in September 2020.[7] On 5 April 2021 Knowles scored his first senior hat-trick during a 4–2 win in a Vanarama National League fixture at Woking, scoring in the 60th, 66th & 79th minutes.[8]
Knowles was loaned to Scottish Championship club Greenock Morton in August 2021. There he suffered a ruptured ACL and missed the remainder of the season.[9]
Knowles made an encouraging start to his career at Boston United by scoring a brace to claim the three points during his home debut against South Shields[13]