It wasn't the sight Vikings coaches wanted to see. At the conclusion of Tuesday's practice, Jared Allen limped toward the locker room with his left ankle taped and a grimace of pain across his face. Allen spent the final half-hour of Tuesday's practice in the trainer's tent adjacent to the field having his ankle examined. He rolled the ankle during 2-minute drill work and couldn't return.

KFAN radio host Dan Barreiro joked with head coach Leslie Frazier on the way off the field that Allen was simply using the injury as a convenient excuse to escape the training camp grind for a few days. "That's a good assumption," Frazier quipped back.

But the Vikings coach seemed slightly more concerned in a discussion with beat reporters a few minutes earlier, noting his star defensive end will require further examination just to make certain the ankle injury isn't more serious.

"We'll look it over," Frazier said, "and determine whether or not we need to do an MRI."

Allen wasn't going to play in Friday's preseason opener against Houston regardless of his health. And he'll almost certainly miss this week's final practice on Wednesday afternoon.

Stay tuned for any updates on Allen's condition.

In addition to Allen's setback, starting safety Harrison Smith twisted a knee during Tuesday's practice. Smith ran a few drills with the defensive backs at the conclusion of practice and sprinted to the locker room afterwards. So his injury certainly didn't appear that worrisome.

"It doesn't seem that way watching him move around," Frazier said. "But you never know. So they're going to check it out to make sure."