• United stretch winless streak to four games
• Another poor and bloodless performance by United
• Result piles more pressure on manager Mourinho
• Home side jeered off the pitch by frustrated fans

MANCHESTER: Manchester United were held to a 0-0 draw by Valencia in a dour Champions League Group H clash on Tuesday which piled more pressure on their under-fire manager Jose Mourinho amid reports linking former Real Madrid coach Zinedine Zidane to his job.

It was another frustrating outing for United and Mourinho, who finally took some responsibility for his team's poor form after defiantly defending his tactics and team selection throughout a patchy start to the season.

He also acknowledged the team's technical weaknesses with a defence that looks shaky every time the opposition come forward and is ill-equipped to build attacks, thus forcing predictable long-ball tactics alien to United's style.

"I think there are things that are difficult for me to say and I think you have enough reasons to criticise me," Mourinho told a press conference.

"The players tried. They raised the level of their efforts. They raised the level of their intensity in spite of the fact we don't have many with that intensity. We don't have the technical quality to build from the back.

"Our attacking players aren't in their best moments of confidence and individual level."

It was United's fourth successive winless outing following a 3-1 Premier League defeat by West Ham on Saturday which came on the back of a 1-1 home draw with Wolverhampton Wanderers and League Cup elimination by second-tier Derby County.

The result left United second in the group on four points from two games, two behind leaders Juventus who maintained their perfect start with a 3-0 home win over Young Boys. Valencia have one point and Young Boys none.

United's next two Champions League games are against Juventus at home on Oct. 23 and in Turin on Nov. 7.

The atmosphere at Old Trafford was rather flat in the first half as United lacked any bite in a contest played at walking pace, with the visitors content to keep them at bay with crisp one-touch passing.

Things livened up slightly after the break and Valencia, always looking more likely to score, missed their best chance when former Chelsea striker Michy Batshuayi blasted over the bar from close range.

Romelu Lukaku forced a pair of good saves from Neto and the visiting keeper also palmed over a Paul Pogba free kick at the other end as United finally showed some purpose up front midway through the second half.

Marcus Rashford hit the crossbar with a vicious free kick from a tight angle in the 86th minute but the home side were jeered off the pitch on the final whistle after another lacklustre performance.

Chris Smalling tried to be positive despite grim United faces on the pitch and the terraces, with scores of fans leaving well before the end of the match.

"We have to stand tall. We're going through a tough patch and we're the only ones who can turn it around," the central defender told BT Sport.

"The dressing room is united. We're sticking together to make sure we turn it around."