THE Reds were knocked out of the Capital One Cup after a 5-1 loss at home to Southampton on Tuesday night.
The Premier League side showed their class throughout but Barnsley once again made too many costly errors.
Steven Davis opened the scoring in the first half when he put the ball home after being set up by midfielder Lloyd Isgrove.
Jay Rodriguez doubled their advantage after the break but Barnsley halved their deficit through Stephen Dawson.
Emmanuel Mayuka restored Southampton's two-goal advantage and the game was put beyond the home side after further goals from Davis and Gaston Ramirez in the dying minutes.
"We defended really poor all over the pitch," said David Flitcroft. "I'm really disappointed with the aspect of how we defended as a team. It's sink or swim time."
Veteran goalkeeper Mike Pollitt made his Barnsley debut having only just signed a 28-day loan earlier in the day.
"I've felt for quite a while Luke Steele was not under enough competition," Flicker added. "I felt I could relieve a bit of pressure on Luke.
"Luke's been rested tonight and it was a good opportunity to try something different."
Barnsley, at the foot of the Championship table, have conceded 17 goals in their first six matches of the campaign and will now return to league duties against Huddersfield Town on Saturday.
