ALLEN PARK, Mich. (AP) -- On the heels of an NFL-best 4-0 preseason record that coach Rod Marinelli says means nothing, the Detroit Lions' focus is locked solely onto official business.
The Lions, who recorded their first undefeated preseason mark since 1993, open the regular season Sunday in Atlanta.
Practices held on Sunday and Monday had a new level of crispness to them, which, Marinelli said, is a sure sign that his team is prepared to begin the meaningful phase of its season.
"They're ready to go," Marinelli said after the Lions' morning practice Monday. "I think they're excited. This is the time of year we've all waited for and we just go back to work each day."
Marinelli said he will use the rest of this week to make final determinations of who will start at several positions.
The right side of the offensive line is beginning to clear up with tackle George Foster and guard Stephen Peterman emerging as leading candidates to start.
Marinelli said his starting defensive backfield continues to be a work in progress as several players continue to battle for a starting job.
"We've still got some work to do back there, decisions to make," Marinelli said. "That thing is pretty close back there."
Marinelli elected to keep 11 defensive lineman on the roster to avoid being hit by a series of injuries at the position as has happened in the early stages of the season during Marinelli's tenure.
Each lineman has earned a roster spot, but Marinelli said that given the nature of Detroit's defensive scheme, having players ready to go as back-ups remains a priority.
"We felt at the end of the day that these were some of the best players on our team," Marinelli said.
Marinelli said that not only does keeping some starting jobs vacant keep the level of competition at a high level, but it also allows players to improve as the regular season approaches. And by now, Marinelli's players are ready to move forward, eager to see if preseason positives can be carried over into another new year.
"Up until this point, you're just practicing and you're just running plays," quarterback Jon Kitna said. "Now, you have a focus of what we're trying to do and how to attack a certain team and you start to get a feel of what you're going to do that week."
Despite playing well in the preseason and a start to the season that potentially could yield some early victories, the Lions won't allow themselves to look beyond Sunday's road test against the Falcons.
"We've been waiting for this week," center Dominic Raiola said. "We're old enough to know that this is for real."
NOTES: The Lions named their captains Monday, establishing some consistency as defensive tackle Cory Redding, linebacker Ernie Sims, kicker Jason Hanson, Kitna and Raiola were chosen by their teammates as captains for the second straight year. "All those guys lead in different ways," receiver Calvin Johnson said. "Those guys are going to push us all the way through." ...Running back Rudi Johnson worked out with the Lions Monday after being cut by the Cincinnati Bengals. Marinelli called Johnson "impressive," stressing his physical running style as well as experience in the league. Marinelli said it is now up to the front office to determine whether the Lions will sign Johnson.