Cardinals GM Steve Keim expressed concern about the offensive line's protection after the Cardinals preseason game vs. the Chargers.

Now the Cardinals are making some changes up front.

D.J. Humphries, the team's first-round pick in 2015, will back to left tackle, this time with the second team.

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The reason is two-fold, according to head coach Bruce Arians.

"He's going to be a back-up tackle for us," Arians said, via ESPN. "And if he's going to dress on Sunday, he's got to be able to play both. So we got to get him a little left-tackle work."

With the possibility of Bobby Massie facing suspension the first three games of the season, Earl Watford and Bradley Sowell are expected to compete for the starting role at right tackle.

(h/t ESPN)