ALLEN PARK, Mich. (AP) -- From his catchy nickname to his sturdy performance on the field, Calvin Johnson often seems indestructible.
So it was a bit startling when the star wide receiver was limited by injuries toward the end of last season, finally sitting out the finale after his Detroit Lions were eliminated from playoff contention.
Johnson had surgery in the offseason on a knee and a finger, both of which caused problems for him in 2013. He still put up terrific numbers for the Lions, but he was held under 100 yards in the last three games he played and couldn't prevent the collapse that kept Detroit out of the postseason.
On Tuesday, ''Megatron'' was out on the practice field, preparing for what he hopes will be a healthier, more successful season.
''It feels great to be out here playing with the guys,'' Johnson said. ''I missed a lot of practice time last year before games. You definitely feel like you need that practice time before a game, just to get on one accord with your quarterback.''
Johnson caught 84 passes for 1,492 yards last season - great stats for almost any player, but his worst output in both categories since 2010. It was never entirely clear how much Johnson's knee was bothering him, but then-coach Jim Schwartz conceded in late December that the star receiver was nowhere near 100 percent.
''It was bad enough where I had to get it drained every week,'' Johnson said. ''The finger, it was stuck at 90 degrees. It's good to have those things freed up.''
The Lions fired Schwartz and replaced him with Jim Caldwell in the offseason, meaning Detroit is implementing a new offense. Quarterback Matthew Stafford will be under pressure to limit the mistakes that plagued him last year - and he should have an easier time if Johnson is back at full strength.
Although Johnson missed only two games last season, he wasn't able to practice all that regularly. That time is valuable even for a veteran who will turn 29 in September.
''You kind of lose your wind a little bit. You know the plays, but I feel that you have to go out there and practice to be able to play at your best,'' Johnson said. ''I'm a firm believer in that. I had experience in the offense, therefore I was able to go out there and still play, but I'm a firm believer that being out there during the week definitely improves your performance on Sunday.''
With Nate Burleson no longer on the Lions, Johnson is now the elder statesmen of Detroit wide receivers, and he's always led by example. It's easier to do that, of course, when he's healthy enough to practice.
''It's nice to have him back and working at full strength. I'm so happy for him,'' center Dominic Raiola said. ''The guy's so tough. It's hard to get him out of there. He'll play through anything. For him to be healthy right now and being out there with the team, that's big time.''
NOTES: Caldwell said injured CB Chris Houston has been excused from practice. Rookie WR T.J. Jones, the team's sixth-round draft pick, was also excused Tuesday. ... Caldwell joked a bit about his reputation for remaining even-keeled. ''There's no need for a whole lot of cussing, screaming, yelling and all that kind of stuff,'' Caldwell said. ''It's a mini quiz out here. I never had any of my professors yelling in my ear when I was sitting at the desk filling out those multiple-choice questions.''
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