LONDON -- Hello from London where Mark Craig and I arrived this afternoon.

Our colleague Jim Souhan attended a welcome function for the Vikings this morning after they arrived following an overnight flight. Souhan reports that Coach Leslie Frazier said three defensive backs -- Chris Cook, Jamarca Sanford and A.J. Jefferson will not practice Wednesday as the team begins preparations for Sunday's game against the Pittsburgh Steelers at Wembley Stadium.

This will be a important story line to follow all week because the Vikings depth is stretched thin with these injuries. Cook suffered a groin injury in the first quarter of Sunday's loss to the Browns. Sanford injured a hamstring and Jefferson is dealing with an ankle injury.

All three players had MRIs before leaving for London. The team obviously will be cautious with these players because those injuries can linger all season if a player rushes back too soon.

A depleted secondary could put the Vikings in a tough spot because the Steelers rank 10th in the NFL in passing offense and only 31st in rushing offense.

The Vikings practice at a field near their team hotel on Wednesday and Thursday. We'll have early updates all week along with videos and lots of other related content.

Also, I'm hosting a live chat today (Tuesday) at starting at noon central. Hope you join me.