The Vikings again had one of the better special teams units in the NFL in 2015, landing in the top 10 in the annual rankings from the Dallas Morning News. But an unforgettable special-teams gaffe ended their season in the 10-9 playoff loss to the Seahawks at TCF Bank Stadium last month.

As you know, kicker Blair Walsh badly missed a 27-yard field goal in the final minute of that loss. That marred what had been a bounce-back season for Walsh, who led the league with 34 successful field goals and rewarded the Vikings for signing him to a contract extension in July.

While his 87.2 percent success rate on field-goal tries during the regular season was near the middle of the pack, the 2015 season was a step in the right direction for Walsh after he was last in the league in that category in 2014. Well, it was until his stomach-punch miss against the Seahawks.

Walsh is not the only question mark for the special-teams unit right now.

Punter Jeff Locke ranked 30th in the NFL with a net punting average of 37.8. It was the second straight season that his net average dipped. So Walsh will have company under that microscope this offseason.

But it was not all bad for the Vikings in that third phase last season. Not at all. The punt coverage team was very good and the Vikings produced big plays in the return game, both punts and kickoffs. And long snapper Kevin McDermott avoided a major miscue in his first season in Minnesota.

Vikings free agents: All three specialists are under contract, but some special-teams regulars are unrestricted free agents, including cornerback and punt returner Marcus Sherels, tight end Rhett Ellison, safety Robert Blanton, running back Matt Asiata and linebacker Jason Trusnik.

Level of need: Moderate. The Vikings need to bring in someone to push Locke and also possibly a kicker just in case Walsh cannot bounce back.

Stat that stands out: 31.8 — yards per kickoff return for wide receiver Cordarrelle Patterson. It was the second time in three NFL seasons that Patterson led the league in kickoff return average. He was the only player last season to score on multiple kickoff returns, taking two to the house.

Burning question: How will Walsh respond after one of the most infamous missed kicks in NFL history? In the immediate aftermath of the miss, he handled himself with poise and professionalism. He also vowed to come back this spring as a better kicker. But it is fair to wonder if Walsh will be able to move on from the crushing miscue. The Vikings aren't expected to kick Walsh to the curb this offseason. But it would not be surprising if they brought in competition for Walsh in case he can't recover mentally.