ALLEN PARK, Mich. -- Joey Harrington, the third overall pick in last April's NFL draft, will start at quarterback against the Green Bay Packers in the regular season debut of Ford Field on Sunday.

"I feel like I'm ready,'' Harrington said Wednesday after his first practice as the No. 1 QB. "I'm so excited to play a whole game again.''

	Joey Harrington will try to improve on his QB rating of 23.8 in his first NFL start on Sunday.

Harrington played behind second-year quarterback Mike McMahon in the first two games, both blowout losses for the Lions, who are 2-16 over the past two seasons.

"This is a little earlier than we wanted this to happen, but we think he is ready,'' Detroit coach Marty Mornhinweg said. "He threw a ton of balls in the preseason, and he's had two regular-season games to learn from.''

Harrington has completed 7-of-18 passes for 52 yards and has a dismal quarterback rating of 23.8. McMahon, a fifth-round pick last year, is 22-of-44 for 275 yards with one touchdown and two interceptions.

"These first two weeks have been great for me to see how the tempo of the game and the intensity picks up,'' Harrington said.

McMahon, who makes about $300,000 a year, knew it was only a matter of time before he was benched in favor of Harrington, who has a six-year contract worth about $36.5 million.

"It was expected,'' McMahon said. "This is the NFL. It's a business. If things aren't going well with your team, it's almost like you have to do it.''

When the Lions chose Harrington instead of a player to fill an immediate need at another position, such as cornerback, McMahon knew he would not be the starting quarterback for long.

"It's almost like, if we're winning, everything will be fine,'' McMahon said. "If not, there's going to come a time when they're going to replace me. That day has come and you got to deal with it.''

Mornhinweg didn't dispute McMahon's assessment.

"This is a brutal business,'' Mornhinweg said. "This isn't fair to Mike, but it was a move we felt we needed to make. I think highly of Mike and like him very much. He has handled this amazingly well.

"He told me that he will be ready whenever we need him. But he is at a point in his career where he is going to be up-and-down, up-and-down, and we need more consistency from the quarterback spot."

Mornhinweg said he thought the quarterback switch would happen before the fifth game of the season, after a bye week, but now believes Harrington has progressed enough to provide more stability.

"I didn't think it would happen this soon, to be honest,'' Harrington said.

Harrington, a 6-foot-4, 215-pounder, was 24-4 as a starter at Oregon and led 10 fourth-quarter comebacks. Last season, he threw 23 TDs with just five interceptions and finished fourth in the Heisman Trophy balloting.

The Lions haven't had a quarterback play in the Pro Bowl since Greg Landry in 1971 and have not had long-term stability at the position since Bobby Layne started from 1951 until Detroit won the NFL title in 1957.

Since then, the Lions have used more than 20 starting quarterbacks -- and have won only one playoff game.