INDIANAPOLIS (AP) — With a five-game losing streak, Indiana can ill afford any more injuries, especially on offense.

Quarterback Kellen Lewis, who missed last week with a high ankle sprain, is still questionable for Saturday's game against Northwestern. Starting guards Andrew McDonald and Cody Faulkner still haven't been cleared to play, either, and backup lineman Dennis Zeigler will undergo surgery Wednesday on his injured knee and will miss the rest of the season.

On top of that, Andrew Means, who leads the Hoosiers (2-5, 0-4 Big Ten) with 333 yards receiving, is wearing a cast on his hand, and his status for Saturday isn't known yet, coach Bill Lynch said Tuesday.

"Without making excuses, injuries have affected our consistency on offense," Lynch said during his weekly conference call. "And we have hit a stretch where we played some pretty good defensive teams."

Four of the five straight losses by Indiana haven't even been close, starting with a 42-20 rout by No. 20 Ball State. The Hoosiers lost 42-29 the next week to Michigan State and have been outscored 116-29 in their next three losses to Minnesota, Iowa and Illinois.

Northwestern (6-1, 2-1) is coming to Bloomington after a 48-26 rout of Purdue.

"Inconsistent is one word," said Lynch, trying to pinpoint the Hoosiers' main problem since their 2-0 season start. "There have been times throughout the course of the last five weeks where the defense played very, very well, and times when they did not play well. Saturday, we were prone to giving up big plays, and what we try to do defensively is to limit big plays.

"In a lot of ways, the offense is the same way," he said.

Sophomore Ben Chappell made his first career start at quarterback last week in place of Lewis and was 12-of-29 for 172 yards in a 55-13 loss to Illinois, but a number of the incompletions were throwaways to avoid being sacked, Lynch said.

"He handled himself well and will continue to improve," the Indiana coach said. "Illinois really came and he had people in his face all night. When he had a chance to throw, he executed well."

The more mobile Lewis might give the Hoosiers better balance.

During the five-game slide, Indiana has managed just four touchdowns rushing and four TDs passing, along with five field goals, and the offensive production has steadily declined.

"Early on, we were running the ball well. Maybe we became a little too reliant on big plays," Lynch said. "We were also taking care of the football pretty well. And we were healthier. Again, I don't want to make excuses. ... Ben has performed well, but we had to make a change in quarterback, and that affects the offensive line. We've got to continue to improve our pass protection."