Jason Fox is starting at right tackle for the Miami Dolphins against the Minnesota Vikings on Sunday, according to a club source.

That is not really a big surprise when one considers starting right tackle Dallas Thomas has missed the entire week of practice with a foot injury.

This is going to be an interesting moment that will test Fox, who was signed to be a backup tackle. He was passed up by coaches when Ja'Wuan James moved from right tackle to left tackle, creating a void at right tackle.

Coaches picked Thomas as the starter.

The issue came when Thomas was largely ineffective as a pass protecter, giving up seven sacks in five starts. But because coaches like Thomas as a run-blocker and coach Joe Philbin defended the second-year player, saying there were "a lot of pictures" of Thomas playing well on tape, the Dolphins stuck with Thomas.

If Fox plays well Sunday it will be interesting to see if the team goes back to Thomas in the season-finale against the New York Jets or keeps Fox in the lineup -- thus admitting he might have been the better choice all along.

Fox and people close to him said nothing during this time he sat behind Thomas but privately were puzzled by the player not getting an opportunity to do that which he was signed to do.

He will get that opportunity on Sunday.

[Update: The Dolphins reported Dallas Thomas as doubtful. Running back Daniel Thomas is also doubtful. Nate Garner is out. Jelani Jenkins, Don Jones and Jamar Taylor are questionable.]