McLachlan attended Lethbridge Collegiate Institute in Canada. He was not highly recruited and decided to join Southern Utah.
In 2019, he saw just 2 games and caught 3 passes for 48 yards. His 2020 season was another short season as he played 4 games and made 12 catches for 120 yards and 2 touchdowns. He did not see action in 2021 and decided to transfer to Arizona.
In 2022, he played in 12 games, making34 receptions for 456 yards and 2 touchdowns. This was his breakout year and put him on some draft radars. However, he decided to return to Arizona for 2023.
This season with Arizona, he played in 13 games, making 45 receptions for 528 yards and 4 touchdowns.