Manchester United winger Ashley Young has been ruled out for two to three weeks with a knee injury, Sir Alex Ferguson has confirmed.
The 27-year-old missed out on the England squad for the World Cup 2014 qualifying double-header against Moldova and Ukraine earlier this month, and Ferguson now expects to be without the player until October.
Ferguson confirmed the problem on Friday afternoon at his pre-match press conference ahead of Sunday's game against Liverpool.
The United boss also said midfielder Darren Fletcher would play from the start in Wednesday night's Capital One Cup tie at home to Newcastle. The Scotland international came on as a substitute in the 1-0 Champions League win over Galatasaray in midweek, his first competitive outing since last November. The player has an inflammatory bowel condition.
Ferguson later confirmed Young's cartilage problem was a knee injury.
The match at Anfield on Sunday will be the first at the ground since an independent panel released its findings on the 1989 Hillsborough disaster, which took the lives of 96 Liverpool fans.
The panel found that South Yorkshire Police had sought to blame Liverpool supporters for the tragedy by instructing its officers to change or amend their statements regarding the day's events.
Ferguson believed the circumstances of the match would make it difficult for both sides, likening it to the game his side played against Manchester City at Old Trafford in February 2008 just days after the 50th anniversary of the Munich air disaster in which eight United players died.
" It is possible (that the build-up could affect players). Human nature is that way," Ferguson said.
"It happened to us at the 50th anniversary of Munich. We were so flat. We just wanted to get it out of the way (United lost that match 2-1)."
Asked about how both clubs had handled the build-up to Sunday's game, Ferguson said: "We have done our bit. Liverpool have done their bit. The messages have been said.
"There is enough pressure on the players. It is an important game for both clubs."