Alan Pardew felt that his side weren't at the races against a Gillingham side who took a 2-1 win at the Priestfield.
The manager knew the relegation threatened Gills would make it a tricky fixture, and the hosts made life difficult as they have done against all of the top six sides this season on their own patch.
"They've got a big, aggressive side, they turn you around constantly," he explained afterwards. "I felt we should have won if we had been at the races but we weren't if I'm honest.
"I've told the players how I feel because the fans that came down here would have expected a better performance to be honest.
"It was very difficult to put into my players' minds how difficult it was going to be here and the penny never dropped until about 65 or 70 minutes when we started to show the quality we've got. Up until then they bossed it, they won every header, got in behind us, caused us problems.
"We had one or two off the pace, José in particular who was sick. He felt alright before the game and we thought he was going to be OK but he was no good. We got him until half time but really he shouldn't have played in hindsight.
"It was a game that was disappointing but ultimately we had to hold our hands up and say they were more prepared than us and up for the occasion and got the win."
Pardew made a handful of changes to his side as he continues to form his ideas for the future and he felt that he learned a lot from what he saw.
"I did make some changes because my focus as well is on next year. I've got to see if one or two players can contribute to next year. They came in and I didn't think they were the culprits.
"It's difficult when you change three or four whether the other boys think you're taking it lightly but we weren't. We wanted to see Lee Barnard and Connolly together because if Rickie's ever injured I need to see how they were going to be and how we will get the best out of them. We didn't get the best of them here because we didn't give them any service.
"Aaron Martin made his debut and I thought he was our best player so I have some sympathy for him. I thought he passed it well and looked comfortable in the shirt and he's about the only player I've got who can be proud of their performance.
"Some of the others like José were perhaps understandable because he was ill but a couple of younger ones and a couple of older ones need to know we've got a very different scenario next year. We will be favourites to win the league and we need to deliver week in and week out, wherever we go, whatever the scenario.
"It's a good test for some of our squad players I put in and unfortunately it didn't come off for them. You learn from every game and I learned some things and we will be guarded and make sure it doesn't happen again.
"I certainly guarantee the fans of Southampton that next week we will play our strongest team in terms of what I feel has done the best for us. It's our last home game and I think we deserve to put our best players on the pitch.
"I had to have a look at one or two today, but that won't be the case next week. I'll pick what I think is my best team and we will make sure the home fans get a chance to say thank you for the season and the players put on a performance to say thank you to the fans."
