The Saints failed to return to winning ways in the Premier League, as they were held to a 1-1 draw by Villa at St. Mary’s Stadium.
The Villans took the lead on the stroke of half time through Joleon Lescott, but conceded the equaliser on 73 minutes when Oriol Romeu found the target.
Koeman has taken to Twitter to give his reaction to the draw and has sent a message to the fans: ‘We march on’.
Southampton are 12th in the Premier League table at the moment with 21 points from 15 matches, eight points behind fourth-place Manchester United.
The Saints will take on Crystal Palace away from home at Selhurst Park in London in the league next weekend.