"Really, it was outside any injury situation we have," Schwartz said. "We're not adding an extra running back. It's one out (Eldra Buckley, who was used exclusively on special teams) and one in."
That said, Best has had two concussions this season and has yet to be cleared to practice this week. ESPN, citing an anonymous league source, reported that Best would not play at Chicago. The team has not officially ruled him out.
"I am not going to respond to anonymous reports and we don't have an injury report today," Schwartz said.
Schwartz said the Lions had no intention of signing a running back when Smith was among 23 other players working out for the Lions last Thursday. That all changed after Smith's workout.
"We had that big workout with an eye toward things that might come up in the second half of the season and in his case, we hadn't really planned on signing anybody," Schwartz said. "But Kevin looked so good. He ran well, he moved well and he was in great shape.
"He's been a productive player when he's been on the field. I guess the silver lining in all that he went through (with the knee surgery) is it gave his body time to heal. He really impressed everybody and we know what we have in him when he's healthy."
Smith, a third round pick of the Lions in 2008 and released after last season, didn't much care why the Lions decided to sign him. After sitting out all season, he's just glad they did.
"I've been away from the game for a long time," he said. "Not knowing if you're ever going to play in this league again, and being still young, being just 24 years old -- having something that you love be in the hands of 32 teams -- it humbles you. When you get that second chance, you don't want to mess that up."
Smith blames his release, though he was just a restricted free agent, on business and his surgically-repaired knee.
"I can't help that I got injured and I think that played a big role in why I wasn't brought back," he said. "But I just focused and realized how much I loved this game and how much I have to prepare for. I can't control injuries but I can still play all out.
"My level of focus is at 100 right now."
Smith isn't likely to play much, if at all, Sunday in Chicago. As he said, "I just got off the sofa like five days ago. I know the offense but it's going to take time for me to play fast."
"Even though I hated being at home, timing is everything," he said. "To be able to join the Lions at 6-2 halfway through the season, man, I feel like the freshest guy in the NFL."
- Coach Jim Schwartz was asked if he thought the Lions were a playoff team. "Honestly, the only thing we can do is concentrate on the Chicago Bears after the bye," he said. "We like our players, we have confidence in our team, but I don't know coaches look at it the way you put it. The New England Patriots won every game (in 2007) until they got to the Super Bowl and lost. If you take anything for granted, this league has a way of humbling anybody. And it has a way of rewarding people that grind it out. The personality of this team is grind-it-out. "
- In the same interview, he gave a more direct answer to whether he cared that his team has been gaining a reputation for being one of the nastiest and edgiest teams in the league.
"It's better than the alternative -- meekest, least aggressive, softest team in the NFL," he said. "People are entitled to their opinion. If you try to fight that, you're going to be miserable in this business. Whatever the perception is, whatever people think of us, that doesn't mean anything to us."
- There is never a bad time for a bye week, but quarterback Matthew Stafford thinks it came at just the right time for the Lions. "I think it is great that guys can get healthy again and a little bit rejuvenated for the second half of the season," he said. "The bye comes at a great time for us. It is an easy separation for us -- Eight games then eight games. The mental part of it is important, too."
- QB Matthew Stafford was at practice Tuesday without any additional wrapping on his sprained right foot. He will take the league's second best passer rating into the game Sunday (112.4).
- RB Jahvid Best (concussion) has not been cleared for practice and isn't expected to play Sunday. Schwartz, though, still believes Best will return this season.
- RB Kevin Smith had rented his suburban Detroit home to rookie Mikel Leshoure after he was released. He said he has no plans to move back in or kick Leshoure out. He is rooming with another teammate in the short-term.
- WR Calvin Johnson has caught 40 touchdown passes since the start of the 2008 season. That's the most in the NFL in that span.
- TE Brandon Pettigrew ranks fourth in the NFL with 41 catches.
- RG Leonard Davis, signed on Sunday, worked with the second offense Tuesday. "Right now my role is to learn the system," he said. "That's all I can do right now. I can't come in and expect to be on the field next week or the week after. It's all trust. I have to learn the system and be comfortable, and then they (coaches) have to have faith in me." Schwartz didn't specifically lay out the team's plans for Davis. "He is a guy we'd been looking at for a while," he said. "At this point, experienced players that have been in a lot of different situations that you can plug in are very important to have. We have been light on the offensive line. We've been going with only eight for a while. We used the bye week to get back to nine."
- DT Sammie Hill (foot) did not practice Tuesday. He was limited during the week leading up to the win against Denver, but he played and finished the game.
- DT Nick Fairley (foot) returned to practice Tuesday, but still appeared limited.
- WR Terrence Toliver (LSU) was signed to the practice squad on Tuesday. OT Casey Bender was released.
- WR Rashied Davis (foot), a key member of the special teams who has missed six games, returned to practice. He was back playing his usual role as gunner on both coverage units. His return allowed the Lions to release CB Anthony Madison on Monday, clearing roster room for RG Leonard Davis.