[3] In 2011, he moved to the FC Copenhagen School of Excellence where he stayed for three years before joining Lyngby Boldklub at U17 level.
[3] Westergaard graduated through the Lyngby academy,[4] before making his first-team debut as a starter in a 3–0 Danish Superliga defeat to OB on 22 April 2018.
[6] Six months later, after Lyngby had reached promotion to the Superliga after one season, he signed another contract extension, keeping him at the club until the summer of 2022.
[12] In his season with Hvidovre, Westergaard scored 5 goals in 25 total appearances,[2] including one in the Danish Cup round of 16 against Vejle Boldklub, which saw his club knocked out after a 2–3 loss.
[19][20] He made his competitive debut for the club on 28 January, replacing Tyreeq Bakinson in the 74th minute of a 2–1 home win over Barnsley.