Rafael Benitez called for Chelsea to be more clinical and again defended Fernando Torres following the unconvincing 1-0 Europa League win at Sparta Prague.
"Eighteen attempts away is not bad, but we have to be more clinical in attack," Benitez said. "The first 20 minutes we were in control. We had some half chances; it was a cross, we weren't there. We were in control.
"After this 20 minutes they were pushing and pushing. The team, as a team, had problems defending.
"We changed a little bit in the second half. I think the concentration of the team was much better, the intensity in defence was much better and then we had more control."
Many of the missed opportunities fell to Torres, a £50million striker who now has one goal in 13 games.
Torres missed a straightforward effort after 35 minutes when teed up by Juan Mata and sliced a second-half shot out for a throw-in in another impotent display at the Generali Arena.
"We have to create more opportunities and the strikers will score more goals," Benitez said. "His work rate today was really good and thanks to him the rest of the team, especially the second line of offensive players, they could create.
"His job today was push-and-run and keep their defenders deep so he could create space for the other players.
"Everybody expects from a striker just to score goals, but he's doing also a great job for the team."
After ending Sparta's 11-match unbeaten home run in Europe, Benitez is now optimistic of progressing to a last 16 tie against Ajax or Steaua Bucharest.
"We have scored the away goal and we have to finish the job at home," he said. "We know it will not be easy." Chelsea were playing in the Europa League for the first time since 2002 and at times appeared reluctant to partake in the second-rank European competition.
Benitez said: "That is the competition that we have to play now. It's a European competition and they (the players) have to realise it's an opportunity to win a trophy.
"I'm sure if we can progress they will see the option and hopefully we can keep the team playing well and winning games, until the end (final)."
Sparta coach Vitezslav Lavicka felt Chelsea were ruthless in the end in his side's first competitive match since December 6.
"From the 60th minute we were under pressure," Lavicka said. "We lost balls when we were attacking. Then the opponent had the chances. Unfortunately we didn't have the energy and the opponent punished us with the goal they scored.
"It was a factor, but it's not an excuse for us. In the Czech Republic we have a winter break and that's what we have to deal with. We tried to prepare as best we could but the opponent was still very strong."