How is he doing?
Gillingham have taken a number of young Saints players on-loan in recent seasons and Slattery joined them in January. He made seven starts but has unfortunately been ruled out until April with an ankle ligament injury.
At 22, Slattery still has time on his side to work his way back into plans with Saints. However, his lack of first-team opportunities in the past does suggest that his future in senior football may lie elsewhere eventually.