DETROIT -- Ndamukong Suh is back practicing, Nick Fairley is not, and once again the Detroit Lions don't have a full complement of starting defensive tackles to learn Teryl Austin's new scheme together.

That Suh has arrived at Lions offseason practices in time for OTAs -- something that has been expected -- will finally end the questions of when the defensive tackle would show up. The unexpected, however, was Fairley's absence for what Detroit coach Jim Caldwell called a "medical procedure."

Like he has said with other players in the past, including cornerback Chris Houston, Caldwell is unsure when Fairley will return and wouldn't say what Fairley had done or what the issue is, so it is unknown when the Lions will actually have their starting defensive tackle tandem together.

For now, that's an issue -- although not really a major one.

The more important thing for Detroit is that Suh is here and in the eyes of Caldwell, he did nothing wrong. In the eyes of many players -- the same players who have seen Suh disappear for the start of offseason workouts in past years -- he did nothing wrong, either.

He did exactly what he needed to, which is show up in camp in the shape they expected. It's why Caldwell seemed surprised when he was asked if Suh addressed the team Tuesday about his absence.

"Why would he do that," Caldwell said. "I don't understand why that would even come up."

Potentially more interesting with Detroit now is what happened with Fairley and how long he will be out. Considering the Lions' expressed plan of the past and present to run their defense through a strong front four, any sort of long-term injury could be an issue.

That's particularly true for Fairley, who has struggled with conditioning in the past few seasons. In that way, he is very much unlike Suh. His conditioning -- he is in nowhere near as good of shape as his defensive tackle tandem partner -- has led to inconsistent play in the past and is why Detroit declined to pick up his fifth-year option.

Now he's hurt and any improved conditioning work he did in the past, depending how long he is out, could end up being mitigated by the undisclosed injury.

With the Lions now back to having their best defensive tackle in town, they just need to wait until both of them can be on the field working out at the same time.