Aaron Barnes admits the number of changes made to Colchester United's starting line-up cannot be used as an excuse for their lacklustre display in the Checkatrade Trophy.

U's head coach John McGreal made seven alterations to his starting line-up for their Group B opener with Southampton under-21s, who ran out deserved 2-0 winners at the JobServe Community Stadium.

Barnes was one of the players who came into the Colchester team, to make his debut for the club.

However, the former Charlton Athletic defender admits they did not do enough to get anything out of the game, on what was a disappointing night for the U's.

Barnes told the Daily Gazette: "Coming in from the weekend (win at Cheltenham), we wanted to keep our momentum.

"We made some changes but that's not an excuse for the performance.

"A few of the boys had a chance to impress but unfortunately didn't do so.

"It's just back to the drawing board.

"We let ourselves down where it really mattered, in both boxes.

"We had chances that we didn't take and the goals that we gave away were quite sloppy, as well.

"That's where the game was lost for us."

McGreal switched things around at half-time, reverting to a 3-5-2 formation and sending on Ryan Gondoh for Sammie Szmodics who was taken off as a precaution after picking up a slight knock in the first-half.

Colchester enjoyed more possession as a result but having trailed to Marcus Barnes' first-half strike were unable to secure an equaliser and Michael Obafemi wrapped up Saints' win with a goal in stoppage-time.

"We had a lot more of the ball in the second half and were pressing quite hard," added Barnes.

"But again, I don't feel we created as many clearcut opportunities as we wanted to.

"We changed the system and that helped us get more of the ball but at the end of the day, we weren't good enough.

"We have to not dwell on this too much and start again in training, on Thursday."