London: Liverpool's manager Juergen Klopp was struggling to be positive after a 1-0 Premier League home defeat by bitter rivals Manchester United on Sunday in a game where they dominated possession and chances.
His side's topsy-turvy season continued as they largely controlled the match at Anfield before being hit with a sucker punch when Wayne Rooney scored with United's only shot on target.
With Liverpool's only fit striker, Christian Benteke, starting on the bench, and Brazilian playmaker Roberto Firmino again deployed in a less familiar central attacking role, the hosts crafted a number of chances but failed to find the net.
The club's struggle for goals has been a problem all season and against United they reverted to type, having thrilled fans in a dramatic 3-3 draw against visitors Arsenal in midweek.
"I didn't see too many chances for Manchester United and we didn't take ours. Of course it is frustrating," Klopp told the BBC. "We lost in a derby against Manchester United so I can't be very positive at this moment so soon after the game."
Liverpool's search for goals is likely to be Klopp's main concern as the season wears on, with Sunday's defeat leaving them ninth in the standings and eight points adrift of fourth place and the final Champions League qualification spot.
According to statistics compilers Opta, Liverpool have averaged 10 shots for every goal scored this season -- only bottom club Aston Villa have a worse conversion rate.
United, who won the reverse fixture 3-1 and sit in fifth place just two points behind Tottenham Hotspur, have scored from all four of their shots on target against Liverpool in their two league fixtures this season.
Benteke, signed by former Liverpool manager Brendan Rodgers for more than 30 million pounds ($42.77 million), has struggled to secure a starting spot under Klopp, who appears to prefer more mobile forwards than the Belgian target man.
The club's difficulties, however, are not all in attack as their porous defence continues to struggle with set-pieces.
United's goal came from a short corner that was taken quickly and whipped into the area by Juan Mata, with Marouane Fellaini's header coming back off the crossbar and Rooney smashing home the rebound.
It was the seventh goal Liverpool have conceded from a corner in the league this season according to Opta, more than any other club.
"The goal was to defend and we didn't do it," said Klopp. "That is our responsibility. We have to defend set pieces better."