While the Vikings figure to start the season with a promising group of three tight ends, they won't have perhaps their best blocking tight end for at least the first six weeks of the season.

The Vikings will start the year with David Morgan on the physically-unable-to-perform list, according to a NFL source, while Morgan continues to deal with the knee injury that hampered him for much of last season. Morgan had arthroscopic surgery on the knee injury after last season, but lingering issues sidelined him through training camp, and he'll spend the start of the season on the PUP list trying to get healthy.

Morgan can return to practice with the team after the sixth week of the season, and the Vikings have three weeks from the point they bring him back to practice to decide whether he's ready to return to the active roster or whether he'll need to finish the season on injured reserve.

A sixth-round pick out of Texas-San Antonio in 2016, Morgan has carved out a role on the roster as a blocking tight end and versatile special teams player who filled in for Kevin McDermott as the long snapper after McDermott lost part of his pinky finger last September against the Rams. Morgan has never caught more than 10 passes in a season, but if he's healthy enough to return later this season, it stands to reason the Vikings could keep four tight ends on the roster, adding him to the group that includes Kyle Rudolph, Irv Smith and Tyler Conklin.

The team released Cole Hikutini on Saturday, according to a NFL source, opting not to keep the 2018 practice squad member on their active roster.