His first appearance of 2007–08 came as a 75th-minute substitute in a 2–0 defeat away to Darlington on 11 August 2007 and following a 2–1 away defeat against Bradford City on 25 August he said "I'm pleased with my form at the moment because I've been working hard to try and stay in the team and I'm happy that things seem to be going well for me at the moment". Mackin joined Conference Premier club Droylsden on 24 January 2008 on a one-month loan, having made seven appearances for Wrexham by that point in 2007–08. He made his debut two days later in a 1–0 home victory over Kidderminster Harriers and on 31 January 2008 the loan was extended until the end of the season after earning "rave reviews" for his performances. His only goal for Droylsden came in the 70th minute against Torquay United on 1 April 2008, which was their only goal in a 2–1 home defeat. He made 15 appearances and scored 1 goal for Droylsden before returning to Wrexham after being recalled from the loan in April 2008. The four appearances he made following his return were described as "battling", and the last of these included his first goal for Wrexham in a 4–2 win away to Lincoln City on 3 May 2008, which was Wrexham's final match in the Football League before their relegation to the Conference Premier. He later commented "I got a little touch on it and I'm not sure if the defender got the final touch but it went straight in and I'm very pleased with it!" He finished the season with 11 appearances and 1 goal for Wrexham, with opportunities in the team again being rare.