He's previously spent time at Blundell Park on loan in 2011 from the Tigers and made his debut in the 5–0 win against Ashington in the fourth qualifying round of the FA Cup, and was named man-of-the-match.
Conor made his league debut on 5 November, playing the full 90 minutes of a 2–2 draw against Bath City. His loan was later extended until the end of the season and was awarded the club's Supporters Young Player of the Season award.
The left-back has also had loan spells with Chesterfield, Carlisle, Dundee United and Scunthorpe in the last three seasons.
With injuries to defenders Gregor Robertson and Josh Gowling, Conor is set to go straight into Tuesday's squad to face FC Halifax Town.
Check out this beauty from Conor for the Mariners v Forest Green.