UNIVERSITY PARK, Pa. -- Penn State quarterback Daryll Clark has been given the green light to start Saturday against Iowa.

But Clark is wearing a green jersey with a cross on it in practice this week while recovering from a mild concussion suffered in the Nittany Lions' last game, a 13-6 victory against Ohio State.

The green jersey means hands off for all defenders. No one is allowed anywhere near Clark.

"I've been taking every rep since the beginning of the week," Clark said yesterday. "I think [coach] Joe [Paterno] is just trying to protect me so I don't get any other hits."

Clark, meeting with reporters for the first time since being injured and knocked out of the game against the Buckeyes 12 days ago, said there was a span in the fourth quarter where he blacked out and doesn't remember anything.

"I remember getting hit and I played, I think, maybe six or seven plays after that, and I blacked out," he said. "I don't remember anything that happened until I came to, and we were up, and I was on the sideline.

"There was a big gap. I looked up at the clock and it was 13 [minutes], and the next time I looked up it was 6 minutes -- in a matter of seconds."

During the final series of the third quarter, Clark ran around the right end for a 7-yard gain. But he was sandwiched between Ohio State defensive linemen Cameron Heyward and Nader Abdallah.

Abdallah was helped off the field after the collision, but Clark stayed in the game.

"I was pretty messed up, but I didn't want to come out," Clark said. "I just tried to continue to play and tried to shake the cobwebs out."

Clark, who had two series of medical tests during the off week, said he has since learned that his head also might have bounced off the knee of Ohio State linebacker James Laurinaitis.

"It was like a boom-boom hit and I remember having a big ring in my head," Clark said. "Usually you get a hit like that, and it's a head hit, you get a little ringer and you are able to shake it off the next play. I kind of knew that this might have been a concussion because that ring did not disappear until maybe the next day."

Clark completed a 7-yard pass to tailback Evan Royster on the first play of the fourth quarter, then left the field just before Kevin Kelly missed a 45-yard field goal.

"Once I got to the sideline, and the doctors looked at me, they said I didn't look good," Clark said.

Backup quarterback Pat Devlin relieved Clark on Penn State's next series. There was 10:38 remaining in the game and the Lions were trailing, 6-3. Devlin scored the go-ahead touchdown on a 1-yard sneak and engineered a field-goal drive.

Clark can't recall Devlin's touchdown.

"I don't remember," Clark said. "There were a lot of people that were talking to me on the sideline, just saying I was kind of mad because of the fact I wasn't in the game. I don't remember that at all."

Clark also said he didn't realize that Devlin had led the Lions to 10 points in the final 6:25 "until after the game."

"Then I went to him and told him he did a good job," Clark said.

Clark, who also had a minor concussion against Michigan in 2006 after replacing injured starter Anthony Morelli, is directing an offense that leads the Big Ten Conference in three of the four major categories. No. 3 Penn State ranks in the top 15 nationally in rushing offense, total offense and scoring offense.

A first-year starter, Clark has completed 63 percent of his passes (126 of 200) for 1,652 yards, with 11 touchdowns. He has tossed just two interceptions and leads the Big Ten in pass efficiency.

"He's anxious, obviously, to get back in there," Paterno said. "He's been having a great year. He's been one of the leaders on this team."

Clark is the Lions' third-leading rusher with 229 yards. He has accounted for eight touchdowns.

"I think he's really ready and he's prepared to go against Iowa," wide receiver Deon Butler said. "He knows that they're a tough defense. He knows he's going to have to bring his best game. And I think he's ready to rebound."

NOTE -- Defensive end Aaron Maybin, Paterno and Clark are among 15 semifinalists for three national awards presented by the Maxwell Football Club. Clark is one of only two Big Ten Conference players up for the Maxwell Award, presented annually to the country's outstanding college football player. Maybin is the lone defensive end from the Big Ten to merit consideration for the Chuck Bednarik Award, given to the top defensive player. Paterno is among the nominees for the coach of the year honors, the George Munger Award.

• Game: No. 3 Penn State (9-0) at Iowa (5-4).

• When: 3:30 p.m. Saturday.

• TV: WTAE.