Slattery joins on loan until the end of the season after arriving at the Gills on Thursday and joins Southampton teammates Tom O’Connor and Tyreke Johnson in ME7.
He is available for selection for Gillingham’s trip to Accrington Stanley on Saturday, and has been assignment shirt number 20.
Slattery began his youth career at Chelsea before joining the Saints’ academy in 2008.
He signed his first professional deal at Southampton in 2017 and was named as a starter for the first time in January 2019 against Derby County in the third round of the FA Cup - a 2-2 draw before Derby won the replay.
In January 2020, he joined Eerste Divisie side De Graafschap on loan, where he made five appearances and scored one goal. He is also the captain of the Saints’ ‘B’ team.
What it means
Gillingham were light in midfield options after Josh Eccles, Scott Robertson and Declan Drysdale all returned to their parent clubs, but that did open the door for more loans to go into Gillingham, and the Blues have used that opportunity.
Slattery may have to wait for his opportunity with Kyle Dempsey and Robbie McKenzie seemingly the first-choice pairing in central midfield, but if one is to play in an advanced role - as they often have - Slattery will slot in nicely.
“There is no doubt he is a talented boy and that is the reason he had lots of clubs keen to secure him on loan.”