ALLEN PARK — Missing time at training camp is especially crucial for a rookie. Even more so this year. Thanks to the NFL lockout, rookies have been thrown into the fire at training camp.

Two of the Lions five drafted rookies — DT Nick Fairley and WR Titus Young — have come up with injuries less than a week into training camp.

While Fairley didn’t seem to think his foot injury was too serious after someone stepped on it during a pass-rush drill on Monday, coach Jim Schwartz couldn’t declare it short-term or long-term on Tuesday. That isn’t a great sign for Fairley whose left foot was in an orthopedic boot on Tuesday.

“(We’re) having a lot of different people look at his stuff. He’s down for now,’’ coach Jim Schwartz said after practice.

Young practiced on Friday and has been out ever since with a leg injury.

Both are missing valuable time and lessening their chances to make an immediate impact on the team.

Running back Mikel Leshoure, a second-round pick, seems to be fitting in quickly with the Lions’ offense.

Doug Hogue, a fifth-round pick linebacker, is making the most of camp so far. With many free agent linebackers unable to practice until Thursday he’s getting plenty of reps.

“It’s fast, I’m still earning the system and things like that. These guys know where they’re going. An inch off makes the difference, I’m getting the gist of it, learning the speed,’’ Hogue said.

Offensive tackle Johnny Culbreath, a seventh-round pick, is also getting plenty of reps with both starting tackles — Jeff Backus and Gosder Cherilus — sidelined with injuries.

(Follow me on Twitter @PaulaPasche.)