EDEN PRAIRIE, Minn. -- The Minnesota Vikings got one of their two injured linebackers back on the practice field on Friday, but it appears they could be without the other one on Sunday.

Anthony Barr, who hasn't practiced in two days with a low back injury, returned Friday, and it appears he'll start Sunday against the St. Louis Rams. Kendricks, on the other hand, left after team stretches and Audie Cole took his spot at middle linebacker in the base defense. Kendricks, who is dealing with a rib injury, would appear to be hard-pressed to play against the Rams.

Rib injuries are especially tricky for linebackers, whose jobs involve running and open-field contact on just about every play. Chad Greenway tried to play with a rib injury last year before breaking his ribs in Week 3 against New Orleans and wound up missing three games because of it. Considering how valuable Kendricks has become to the Vikings' defense in such a short time and how painful a rib injury can be at his position, the Vikings might be wise to exercise caution with the rookie.

Sharrif Floyd also was not practicing on Friday, suggesting he could miss a third consecutive game after having surgery to remove cartilage from his knee. Wide receiver Stefon Diggs, who was limited Thursday with a hamstring injury, was with the team during the open portion of Friday's practice.