Calvin Johnson and Haloti Ngata were no-shows for the Detroit Lions at their OTA on Thursday.

“No injuries,” Jim Caldwell said. “This is not mandatory. There’s going to be guys from time to time, there are going to be a number of guys that aren’t here. There are going to be different situations that are going on, some of them personal, but there’s no injuries, no.”

Johnson, at least, was there earlier this week based on pictures posted on the team’s official website.