Gareth Barry has lamented Aston Villa's lack of strength in depth and hinted that improvements to the squad could be made when the transfer window opens in January.

Villa lost 3-1 away to Liverpool on Saturday, forfeiting their unbeaten run that stretches back to the David O'Leary era, but their shortcomings were exposed for the most part.

Barry, the captain and midfield player, said that the defeat owed more to Liverpool's form than to Villa's failings but the gap between the two teams was significant.

The loss of Gavin McCann, through injury, seemed to affect the visitors and their midfield was outclassed, particularly in the first half.

"We can't knock ourselves too much," Barry said. "You've got to give credit to Liverpool in the first half. That's some of the best football I've played against; like the Liverpool name, pass and move.

"We struggled to get near the ball in the first half and, when we did, credit to them for closing us down. We did miss Gavin McCann, but the loss of Luke Moore has forced us to change our formation."

Under Martin O'Neill, Villa began the season playing a variation of 4-3-3, but injuries to McCann and the speedy Moore make this difficult. "You can't just play with one dimension and we need to learn to play with a 4-4-2 if we're going to improve," Barry said.

"We'll learn a lot from the first half today and take some encouragement from the second half. Maybe the lack of strength in depth is showing up a bit. The personnel is probably not there to play a 4-3-3 formation and that is after just one injury, but the manager is looking at that all the time and hoping to build.

"We're disappointed. It's hard to be calm when you're disappointed. It's been a good unbeaten run but finally it's come to an end, and maybe that can be a good thing.

"We can focus on winning on games instead of all the talk of us being the only unbeaten team in the league. We have to focus and battle on."

O'Neill, the Villa manager, said that his players endured a reality check but he was impressed with how they played in the second half.

"We were a bit in awe of the situation," O'Neill said. "Liverpool played very well in the first half, but we contributed to that. We didn't get close enough to them and they punished them, like a very good side will do.

"We showed spirit and determination in the second half and that has epitomised the side for much of the season.

"We are aspiring to where Liverpool are. It will take a bit of time, but after ten games I have been very pleased with the team and their willingness to fight back.

 "It was probably a reality check. If we had gone on like we did in the first half, I would have been very disappointed, but we now see it is not all about determination and character. It's about quality."