Steven Gerrard has said Liverpool's younger players took their "foot off the gas" against Notts County but accepts the entire team is responsible for the groin injury that threatens to sideline Kolo Touré for a lengthy period.

Touré has made an impressive start to his Anfield career but is expected to miss Sunday's visit of Manchester United after pulling up during extra time in Liverpool's 4-2 defeat of the League One side. Joe Allen and Aly Cissokho are also unlikely to feature after a costly victory for Brendan Rodgers.

The Liverpool manager wants to bring Mamadou Sakho to Anfield from Paris Saint-Germain before the transfer deadline but the French club are reluctant to sell the 23-year-old defender. In the absence of any in-comings, out-of-favour Martin Skrtel is likely to partner Daniel Agger against the Premier League champions.

Touré tore a groin muscle at the 2008 African Cup of Nations with Ivory Coast and Gerrard admits his team-mates must shoulder blame having failed to hold a comfortable 2-0 lead against Chris Kiwomya's side on Tuesday. "There's no doubt playing extra time was a blow for us," the Liverpool captain said. "We ended up having to play 120 minutes and a lot of the players who are probably going to be starting on Sunday have played too much football. The plan was to get the game won and done and dusted and try and rest a few for Sunday.

"The only good thing is that because we are at the start of the season, everybody is fit and should be fresh so I'm hopeful it shouldn't be too much of a problem. But Kolo's injury came in extra time. He wouldn't have done that during normal time. We have ourselves to blame for his injury. We have to take responsibility for that. Sunday is a massive game. Kolo has started the season very strongly and we will be very disappointed if he is not fit for the weekend. But it's not looking good. He left the ground on crutches."

Daniel Sturridge admitted Liverpool were guilty of complacency in the second half against Notts County and Gerrard believes that stemmed from the number of young players in an otherwise strong Rodgers' team.

"The game got too easy," said Gerrard. "When you have a lot of inexperience in your team, you can sometimes take your foot off your gas and get punished and that's exactly what happened. We were in complete control and it looked like we were going to win by three, four or five. But when you have a lot of youngsters in your team who maybe don't know how to see a game out, sometimes you can make it very difficult for yourself and that's what we did."

Liverpool struggled to turn encouraging displays into wins against the six teams that finished above them in the table last season, beating only Tottenham.

Gerrard believes the additions to the Liverpool squad this summer, plus Sir Alex Ferguson's retirement at Old Trafford, can assist in closing the gap on United.

"That's something we have been trying to do for a long time, not just with changes in the summer," the midfielder said. "For a long time, the gap between ourselves and [Manchester] United, Chelsea and now Manchester City has been too big. Each year we have been trying to close that gap, so really this season isn't any different in that respect but it does feel slightly different this year.

"The team spirit is really good and there is a belief within the squad. The changes the manager has made during the summer are really positive and hopefully there are still one or two more players to come in.

"We didn't get what we deserved from the big games last year. To try to improve on that this season, we have to put in the same effort but learn to start turning draws into maximum points. For me, United and Everton are still the biggest two games of the season."