Chicago Bears coach Lovie Smith on Friday remained true to past practices and stepped around the touchy issue of his future in Chicago possibly hinging on a win Sunday over Detroit.

Rather, Smith focused on the importance of the game, which the Bears must win to make the playoffs. (They also need a Packers win over Minnesota.)

"It's the nature of the game, as I see it," Smith said about one game determining so much. "And for us, it's about getting into the playoffs. If you get into the playoffs, a new season starts. We realize what the sixth seed has done in the playoffs. So it's no more than that for us. We're a good football team and good football teams need to find a way to get in the playoffs and have an opportunity to advance. No more than that."

Unga up: Running back Harvey Unga, a supplemental draft choice in 2010, has been promoted to the 53-man roster and DE Cheta Ozougwu has been waived. That gives the Bears three healthy running backs available for Sunday. Backup Armando Allen (knee) is questionable but hasn't practiced this week. Unga has been with the team for three preseasons and has also been on the practice squad this year in Weeks 1-4 and 13-16. The 6-foot, 237-pounder is more of a power runner than any of their other available backs, and he can also play fullback.

Secondary importance: The Bears aren't putting too much weight on reports that Lions WR Calvin Johnson missed two straight practices due to ankle and knee injuries. Johnson is officially listed probable, so he'll be playing.

What has to concern Chicago coaches is that Bears' Anthony Walters is making his first NFL start at free safety.

"He played some last week so that 'first time he's played stuff,' you have to go through ... he's past that," coach Lovie Smith said. "He's been around a long time. We feel comfortable with him. That's the reason why he's on our roster. 

"Normally, we go through a few safeties. That's just a part of it. They realize that and they prepare that way. So we feel comfortable."

The Bears have already put S Brandon Hardin and S Craig Steltz on injured reserve this year, and starter Chris Conte has a hamstring pull that will keep him out of Sunday's game -- and possibly a playoff game next week, if the Bears make the playoffs.

Catch 23: Devin Hester's focus isn't necessarily returning a punt for a touchdown this week, but just catching the ball. Last week, he let several short punts bounce around that should have been fair-caught. One struck blocker D.J. Moore and resulted in a turnover.

"He'll be the first one to admit that he's got to do a better job," special teams coordinator Dave Toub said. "He's got to realize that when he makes a fair catch, he's the only one -- everyone else has to get out of his way, including our guys.

"We can't let the balls bounce. We let too many bounce in the last game, and it came back and bit us."

Top candidate: For the second straight year, CB Charles Tilllman is the Bears' candidate for the Walter Payton NFL Man of the Year Award. The award is based on players' off-field work in charities. Tillman was one of three finalists last year. The winner is announced at the Super Bowl.

Follow Bears reporter Gene Chamberlain on Twitter @CBSBears.