Johnson, who injured his knee in Palace's 3-2 defeat against Reading last week, underwent an exploratory operation that confirmed the extent of the damage.

Eagles manager Iain Dowie expects Johnson to return for the club's Championship match against Coventry in mid-October, meaning the 24-year-old striker will miss the next four games.

"It could have been a six to eight-week thing but we never thought it was as dire as some people were predicting," Dowie said.

"We hope to have him back for the Coventry game in mid-October."

Johnson had initially feared he would miss eight more weeks before the operation confirmed that damage was less serious than first feared.

England face Austria on 8 October and then Poland on 12 October in their final qualifying games in Group Six.