EDEN PRAIRIE, Minn. -- The Minnesota Vikings were missing a handful of players because of injuries during Thursday's organized team activities. That included left tackle Matt Kalil, who had an operation four or five weeks ago, coach Mike Zimmer said.

Zimmer would not elaborate on the operation, other than to say it was not on Kalil's shoulder. The 2012 first-round pick was limited to individual drills Thursday.

Safety Andrew Sendejo was also out after having an operation on his back recently, Zimmer said, and cornerback Josh Robinson and safety Jamarca Sanford missed time because of pulled muscles during Wednesday's OTA.s

"They're day-to-day," Zimmer said of Robinson and Sanford. "It's nothing much."

Defensive tackle Linval Joseph is working his way back from a previous injury as well, but Zimmer said Joseph -- who signed a five-year deal with the team in March -- is getting close to returning to the field.