(Reuters) - Kansas City Chiefs running back Jamaal Charles will miss the rest of the National Football League (NFL) season with a left knee injury, the team said on Monday.

Charles, who was second in the NFL last season with 1,467 rushing yards, was injured when he was pushed out of bounds while lunging toward the first down mark in the opening quarter of Sunday's loss to the Detroit Lions.

"Jamaal will be placed on injured reserve," Chiefs head coach Todd Haley told reporters during a news conference.

"It's unfortunate for Jamaal because I know Jamaal had high hopes and was excited and had worked very hard to be able to take this to the next level and now he won't be able to do that and I know he's hurting pretty good inside."

The injury to Charles, who had to be carted off the field, is the latest blow to a Chiefs team that many had expected to be competitive this season.

The Chiefs won their division last season but have been outscored 89-10 in their opening two games of the 2011 campaign and were already without Pro Bowl safety Eric Berry and tight end Tony Moeaki for the season.

(Reporting by Frank Pingue in Toronto; Editing by Julian Linden)