ANNAPOLIS, OCT. 14 -- Senior fullback Chuck Smith, who is the Naval Academy's leading rusher, injured his left knee against Air Force last week and will not play at Penn Saturday.

Smith ran only two times for four yards against the Falcons before leaving the game in the first quarter. He has a third-degree, medial collateral sprain. Smith, from Strongsville, Ohio, leads the Midshipmen (0-5) in rushing with 364 yards on 72 carries.

Navy Coach Elliot Uzelac said today he will will replace Smith with freshman Deric Sims, senior Curtis Brown or junior Bert Pangrazio.

Free safety Mike Marchildon also injured his knee against Air Force and will not play Saturday.

"We want to win bad," Uzelac said at his weekly news conference. "We're getting better as a team every week. We just have to keep playing hard."

Alton Grizzard, who last week was the first freshman quarterback to start at Navy since 1974, will start again, Uzelac said. "We felt he did very well, under the conditions. He made a few freshman mistakes, but he showed good leadership and he got the ball in the end zone."

Penn (2-2) will be without starting quarterback Malcomb Glover (broken thumb) and tailback Chris Flynn (bruised knee).