The 19-year-old was sent off inside 90 seconds of his first start on Tuesday evening, with Saints going on to fall to a record-equalling 9-0 Premier League defeat by Manchester United.
Jankewitz subsequently became the latest in a string of players to be subjected to sickening online abuse, with monkey emojis and racist terms directed at him on social media.
Alex Jankewitz was subjected to racist abuse online after being sent-off against Man United
The 19-year-old lasted 82 seconds on Tuesday before his horror-tackle on Scott McTominay
A statement from the club read: ‘Southampton Football Club can confirm that it has identified a number of posts on social media directing racial abuse at our 19-year-old midfielder Alex Jankewitz, following last night’s result at Manchester United.
‘Abuse of any form will never be tolerated at Southampton.
‘Our club prides itself on its inclusive nature, and supporters who stoop to such abhorrent and archaic standards are not welcome as Southampton supporters, or anywhere else within football.
The club are working with police to track-down individuals who made the archaic comments
‘The club will continue to fight every day to remove such people from our sport and our community in order to protect our players, our staff, Southampton fans and football supporters around the world who recognise and celebrate the diversity that makes football special.
‘The club is passing on all abusive messages to Hampshire Police and hope they are able to permanently remove those individuals from our football community.’