Bastian Schweinsteiger gets treatment for an injury during Germany's match against Ghana. ((Joern Pollex/Getty Images) )

German relief at overcoming a tough Ghana side in Johannesburg on Wednesday night was somewhat tempered by the nervy manner of the 1-0 win, and even more so by the worry about its least dispensable player.

Bastian Schweinsteiger, the Bayern Munich midfielder and tactical pacemaker of the team, injured his hamstring and did not last 90 minutes in the Soccer City Stadium. He was replaced by 20-year-old Toni Kroos with less than ten minutes to go.

Germany manager Joachim Löw said he was "optimistic" that 25-year-old Schweinsteiger had left the pitch "in time" to avoid lasting damage, but a member of the medical team later rated his chances to feature in the last round of 16 against England in Bloemfontein "fifty-fifty, at best."

"If he can't play, it won't be a good thing for us", said Löw, careful not to overstate the potential loss. Keeping up morale over the next few days will be a key task should "Schweini" really be ruled out.  

In truth, a Germany side without Schweinsteiger's calm influence and clever passing is almost inconceivable. Since the team lost half a dozen central midfielders to injury this year, Löw doesn't exactly have great options for the center of the pitch left. 

Rookie Kroos (Bayern), more of a play-maker than a holding midfielder, might have to come in, or Jerome Boateng could move up from the left-back spot. Neither of them would inspire too much confidence against Steven Gerrard and Co. on Sunday, however.

Löw admitted to more potential issues. Boateng suffered from a "back problem," while Mesut Özil, the goal-scorer, had "turned an ankle", according to the 50-year-old.

"I don't know how serious it is yet", he added. At least striker Miroslav Klose should be back in the starting lineup following his red card suspension against the "Black Stars." 

Löw said he was excited about facing England. "It's always special against them, a real classic", he said. While the manager singled out the threat of Wayne Rooney — "he can explode at any minute, our defence will face a tough time stopping him" — and was generally happy to down-play Germany's chances — "we are a very young team and they are fantastic, incredibly dangerous" — Wednesday's matchwinner Özil was remarkably bullish.

"It'll be tough, but if he can play to our strengths like we did today, we should be able to win as well."

The problem is, it's hard to see them really play to their strengths without Schweinsteiger, who, at the relative tender age of 25, has matured into the most experienced and composed member of a bright but incredibly young German midfield.