Sir Alex Ferguson faces an anxious wait to discover if Manchester United's Premier League title defence suffered an early blow during his side's Community Shield penalty shootout defeat to Chelsea.

Ferguson had plenty to occupy his mind on the journey back to Manchester on Sunday as he contemplated an injury to Portugal winger Nani that could wreck his plans for life after Cristiano Ronaldo and Carlos Tevez.

Nani had made a significant contribution to United's first-half dominance at Wembley and it was perhaps no coincidence that his departure early in the second half with a dislocated shoulder was the prelude for Chelsea's best period of the game.

After scoring the game's opening goal and tormenting Chelsea right-back Branislav Ivanovic to such an extent that Blues boss Carlo Ancelotti was forced to replace him with Jose Bosingwa at half-time, it seemed Nani was ready to claim the role as Ronaldo's successor.

Instead he will have a scan to determine how long he will be out after leaving the pitch with his arm in a makeshift sling following John Terry's firm but fair challenge.

Nani is certain to miss Portugal's friendly against Liechtenstein on Wednesday (Beijing time Thursday) and United's home opener against Birmingham on Sunday. He may not make the trip to Burnley next week either, forcing Ferguson to rethink his tactics just when it seemed the post-Ronaldo era might not be so troublesome after all.

"We could not put the shoulder back in, so that is the worrying part for us," Ferguson said. "He had done very well and we were very pleased with his performance."

Nani's fitness isn't Ferguson's only concern as he gears up to go for a record fourth successive Premier League title.

With goalkeeper Edwin van der Sar out for eight weeks after finger surgery, Ferguson could have done with a solid display from Ben Foster.

Instead the England international produced an error-strewn performance, which included letting Frank Lampard's shot through his gloves for Chelsea's second goal and punching poorly for Ricardo Carvalho's opener.

Ferguson admitted he must decide whether to stick with the youngster or select Tomasz Kuzsczak against Birmingham.

"Knowing Ben and the ability which he has, he should have done better with the second goal," said Ferguson. "However, it was his first big challenge.

"He has waited a long time, has had his injuries, and in preseason I spread the load between the three 'keepers, and maybe we did not have enough minutes for him."

That wasn't Ferguson's only complaint. He also claimed Chelsea substitute Michael Ballack should have been sent off for the elbow that sent Patrice Evra sprawling in the build-up to Lampard's goal.

"If the referee sees it properly, it's a red card," Ferguson said. "He's elbowed him clearly. The referee's in line and had a clear view so Ballack's lucky.

"But the referee (Chris Foy) made a rod for his own back. He'd stopped the game twice already so I can't understand why he wouldn't do it for Evra."

(AFP via China Daily August 11, 2009)