BOSTON -- Less than two years ago, Brad Lohaus nearly quit basketball because it wasn't fun anymore. Now he is playing with such enthusiasm that his Boston Celtics coaches are trying to calm him down.

On a team that traditionally has relied little on rookies, the 7-foot forward from Iowa has made a strong impression. In the Celtics' NBA season opener, he had eight points and seven rebounds in 13 minutes.

He has continued to contribute and is averaging 4.3 points and 2.8 rebounds in 12.4 minutes per game, although his playing time is expected to drop now that Kevin McHale has returned after missing the first 14 games recovering from foot surgery.

"I don't put much stock in" the Celtics' aversion to using rookies, Lohaus said. "I think if you can help them, you'll help them. If you can't, then you're going to wait."

After an undistinguished college career in which he had three coaches, Lohaus has been impatient to produce after being drafted in the second round despite expectations he would go earlier.

"I said to myself, 'Now I've got to prove that I can really play.' If you go on the first {round}, they {coaches} generally think we'll give him a shot at it even if you look bad in practice," Lohaus said. "When you're taken in the second round, you've got to prove that they should keep you. So I know it made me work harder.

"I worked harder this summer than I have in my whole life as far as getting in shape for basketball, and it paid off."

Because he was excited to be in the NBA, "he was helter-skelter in the beginning," Celtics Coach K.C. Jones said. "He was all fired up. But he grew and now he's ready. He's banging the boards. He's playing good defense. He's making good passes. But he's not out of control."

He almost was out of basketball.

At Iowa, he played one year for Coach Lute Olson. He played two years for George Raveling, separated by a redshirt year in which he was sidelined with a knee injury. In his first three seasons, Lohaus averaged just 4.1 points and 3.2 rebounds per game, statistics he calls "horrible."

He thought about giving up the game during his third season, especially after Raveling left.

"It just wasn't fun anymore," he said, pointing to the coaching change as one factor.

Then Tom Davis became coach and brought a running style that Lohaus preferred to the previous approach in which he played more in the low post.

"When Coach Davis came in, it gave me all the confidence in the world," Lohaus said.

He averaged 11.3 points and 7.8 rebounds per game as a senior, but his stock dropped in postseason all-star games in which he was hampered by illness.

When he slipped to the second round, "I just thought, what did I do wrong? What don't they like about me that they liked about me at the beginning of the year?" Lohaus said.

The Celtics weren't deceived by his postseason problems.

"All-star games very often are guard-dominated . . . He was just like an invisible man," Boston assistant coach Jimmy Rodgers said. "He was a guy that really went the rocky road in college."