James Ward-Prowse apologised to the Southampton fans after they slumped to a 3-0 defeat at Brentford.
Saints remain rooted to the bottom of the Premier League table with some supporters calling for boss Nathan Jones to be sacked following another sorry display.
“We can only apologise to the fans because we know that’s not good enough,” skipper Ward-Prowse told the club website.
“I think individually when you step out on to the pitch in the Premier League you have to show up, you have to run your heart out and give everything.
“I don’t feel like we’re doing that at the moment and that’s the disappointing thing.
“It’s really important when you come away to a place like Brentford you know it’s going to be tough, it’s a team that’s in a positive moment.
“We have to be more resilient, we have to be tough to beat at first to give us a chance to go on and win it.
“But when you give goals away as stupid as we have done in the last two games and probably throughout the whole season, it makes your task a whole lot more difficult. It’s only us to blame.”
Ben Mee’s header put the Bees ahead and Bryan Mbeumo doubled the lead before half-time, with Mathias Jensen sealing the victory with 10 minutes left.
Brentford are now up to seventh following a run of nine league matches without defeat.
Bees boss Thomas Frank said: “You can see how strong the squad is. They are full of confidence in the way they’re playing. I really like that.”