Ernesto Valverde admitted Barcelona's away form was a cause for concern after the Spanish champions fell to Granada.
Ramon Azeez headed the hosts into the lead after only two minutes before an Alvaro Vadillo penalty midway through the second half sent the promoted club to the top of the standings in La Liga on Saturday.
Barca enjoyed 74 per cent possession but only mustered one shot on target throughout the 90 minutes. The setback means Barca have taken just seven points from their first five matches, the Catalan club's worst start to a La Liga season in 25 years.
"I'm worried because away from home we're not getting good results. No wins from four away games this season is a clear symptom that we are not in a very good situation," Valverde told reporters.
"Some of our players joined the squad late but we did not play well today and we have not been playing well away from home lately. We dominated the play but couldn't manage to create many chances and we never looked like getting back into the game."
Lionel Messi was named among the substitutes as the Argentine forward continues to work his way back to full fitness following more than a month out with a calf injury.
Valverde called on his captain at half time along with 16-year-old Ansu Fati, who had scored and provided an assist on his full debut in last week's 5-2 drubbing of Valencia, but neither player was able to ignite Barca's front line.
Barca have not won an away game in any competition since April and were fortunate to return with a draw from their Champions League opener against Borussia Dortmund in midweek.
Valverde also said he was concerned about Barca's poor defensive record. Barca joined Real Betis as the only team in the league to have shipped nine goals this season, and the Spaniard said he shoulders most of the responsibility for the team's shortcomings at the back.
"It's clearly not a very good statistic for us and not in line with what we have been doing in the last few years," he said.
"The players are the actors, but in the end the coach is the one who is responsible for what happens. You can always lose a game but when you do you should feel that you deserved to win but that was not the case today."