The Vikings coaching staff and front office are in the process of fully evaluating their roster as they plan for the opening of free agency in March as well as April's NFL Draft. As General Manager Rick Spielman, head coach Leslie Frazier and their respective staffs put their heads together, the Access Vikings team is doing the same. We are in the middle of delivering snapshot evaluations of every position group. Today, we look at the tight ends. TIGHT ENDS Get excited: You want something to get excited about? Check out Kyle Rudolph's birthdate: 11-9-89. The 2011 second-round draft pick will have nearly three full seasons behind him before he turns 24 years old. He's also 21 months younger than quarterback Christian Ponder, which means, barring injury and a regression by Ponder, these two should be together for a very long time. With 53 catches this season, Rudolph came within one reception of doubling his rookie total. He came within five yards of doubling his receiving yards total and tripled his touchdown total to nine. Rudolph also became a better blocker. He'll never be a dominant blocker, but he definitely used that 6-5, 258-pound body to help move aside some of those eight and nine men who were stacked in the box to stop Adrian Peterson.Rudolph already is a good player. But he's nowhere near reaching his full potential. He's a hard worker, so he'll do his part to get there. Now, it's up to the Vikings to add some quality receivers to help him out.Everyone talks about what a bonafide No. 1 receiver would do for Peterson and Percy Harvin. But think what it also would do for Rudolph to have room to work the intermediate zones against smaller safeties or slower linebackers.Rudolph had a career-high two touchdowns in the Week 3 upset of the now-NFC champion 49ers. But he also had three games in which he didn't catch a single pass. That should never happen, and it won't if the Vikings upgrade their receiving corps with a legitimate No. 1 down-the-field threat and more overall depth. Keep an eye on: The Vikings list Rhett Ellison as a fullback. For our purposes here, we'll consider him a tight end that can play fullback. Or we'll just go old school and call him a good football player.Ellison told reporters a nice story on draft day last year. Ellison said he was sitting on a lake crying after the Vikings selected him in the fourth round. He said he never expected to be drafted.Don't believe him. OK, believe the parts about the lake and the crying. But the part about not thinking he'd be drafted is just a blue-collar kid trying to be humble.Ellison caught only seven passes for 65 yards, so we're not talking about the next Tony Gonzalez here. But we might be talking about the next Jim Kleinsasser, only a little smaller but faster and more athletic. It didn't take long to see that Ellison clearly was the second-best tight end on the team. Whether his growth was stunted by the team's attempts to involve high-priced free agent John Carlson is hard to tell. But for a rookie fourth-rounder, what Ellison gave the Vikings on special teams and on offense was well worth a fourth-round pick. Reason for worry: This could be off target because a man can't read another man's mind, but John Carlson doesn't look like a guy who enjoys playing football anymore. The Vikings made him their priority in free agency a year ago, whisking him from under the Chiefs' noses with a five-year, $25 million deal that brought the native Minnesotan back home. But he never got up to speed following a knee injury on the second day of training camp and was slowed again when he suffered a concussion during the season.Carlson finished with just eight catches for 43 yards, a 5.4-yard average with a long of 14, and no touchdowns. He spent 14 games (six starts) either not being part of the game plan or being unable to get open when he was.The Vikings argue that Carlson's blocking was exemplary and went overlooked. That's true. He gives good effort. But it's also true that the Vikings had much grander plans when they signed Carlson. The Vikings envisioned an offense similar to New England's, which uses two pass-catching tight ends and a slippery slot receiver as their focal points (other than the three-time Super Bowl-winning future Hall of Fame QB, of course). Carlson's inability to fulfill that role – for whatever reason – was a big blow to the passing attack this season.Carlson is 28, so he's still young enough to surprise us. But one certainly has reason to wonder if he can ever be the same player who began his NFL career by catching 106 passes and 13 touchdowns in his first two seasons in Seattle.Carlson hasn't looked the same since suffering a gruesome-looking concussion in a playoff game at Chicago during the 2010 season. He missed all of 2011 with a shoulder injury and obviously struggled in 2012.The Vikings shouldn't give up on Carlson. Barring a surprise acquisition at tight end, they should head to Mankato with the same intentions they had for Carlson last summer. But they also shouldn't just hand him a 2013 roster spot based on how much he makes and what he did in 2008-09.