Brendan Rodgers' side were cruising 2-0 at half-time of Tuesday's Capital One Cup second-round tie against Notts County before a second-half lapse saw the game head into extra time.
Liverpool won 4-2 in the end, but the victory came at a price as Toure was carried off on a stretcher and is now doubtful for Sunday's Premier League encounter with fierce rivals Manchester United.
And Gerrard believes he and his team-mates have to share the blame for not beating the League One side in normal time.
"There's no doubt playing extra time was a blow for us," Gerrard is quoted as saying by The Liverpool Echo.
"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.
"There's an international break coming up, so fingers crossed he doesn't miss that many games for Liverpool."
Following a start to the season that includes three wins from three in all competitions, Gerrard believes the Anfield club are close to breaking back into the leading pack in the Premier League.
"For a long time, the gap between ourselves and United, Chelsea and now Manchester City has been too big," he told the club's official website.
"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."