Patriots wide receiver Kenbrell Thompkins is going to have to prove he belongs with the Patriots one more time in 2014. (Elise Amendola / AP photo)

By Zuri Berry, Boston.com Staff

If the Patriots are going to win the Super Bowl, they have to upgrade a select number of positions and bring in some capable competition.

A cursory look at New England’s roster will show that two positions immediately need revamping: defensive tackle and wide receiver.

That’s where the 2013 Patriots underachieved the most.

But that doesn’t mean all of the players in those positions should fear for their jobs. Just some of them.

And there are others, too, who should be concerned about their standing going into 2014. The Patriots tinker quite a bit with the bottom half of their roster in the offseason with hopes of creating a competitive environment come training camp. There are a select number of players on the team, either because of their performance or because of their contract, who have to face the fact that they are sitting on the bubble.

That includes:

Kenbrell Thompkins — Given a 3-year, $1.493 million contract with $5,000 guaranteed after winning a job out of training camp, he was less than stellar in an injury-riddled season. He caught 32 passes for 466 yards and four touchdowns. But he also had a number of drops (5), plays that kept him off the field while coaches favored fellow rookie Aaron Dobson. He had two fantastic games, catching the final touchdown against the New Orleans Saints and tearing up the Atlanta Falcons for 127 yards and a score. There’s also the issue of the number of bodies for Thompkins. He still has to compete with Dobson, Josh Boyce, and Julian Edelman for snaps, all of whom were outside wide receivers. Edelman is the only free agent of the bunch while Dobson and Joyce are Patriots draft picks, making the other rookies much more valued commodities.

Danny Amendola — His contract is his detriment. He was paid a handsome sum (5 years, $31 million) to be the Patriots’ new slot receiver. But after a fine performance in Week 1, he found himself continually injured and having a tough time performing consistently. His lack of playing time likely contributed to his lack of chemistry with Tom Brady, who targeted him only once in the AFC Championship. Amendola, for his part, dropped it. He caught 54 passes for 633 yards and 2 TDs in the season.

Joe Vellano — The Patriots rookie defensive tackle was never guaranteed to make the team out of training camp, helped in part by Armond Armstead’s unavailability. He substituted for Vince Wilfork and Tommy Kelly as the team’s third defensive tackle until Wilfork, then Kelly, went down with season-ending injuries. But he had only 12 hurries while playing 672 defensive snaps, 322 against the run, according to ProFootballFocus.com. His play was mired in part by a bad outing against the Denver Broncos in Week 12, the same game in which Knowshon Moreno ran for 224 yards. Going into his second season, he has to prove the he belongs on a team that will get back Wilfork, Kelly, and Armstead.

Isaac Sopoaga — It wouldn’t be a surprise if Sopoaga was cut sometime this offseason. The Patriots traded for the defensive tackle, hoping he could help shore up the team’s run defense. But he was a healthy scratch for the team’s final four games. They gave up a fifth round pick for him and paid a prorated portion of his $1 million salary in 2013. He’s slated to make $3.5 million in 2014 and 2015.

Bill Belichick could easily target his tight ends group, the secondary, and the interior offensive linemen for upgrades as well. Safety Adrian Wilson will already be in place to compete while offensive linemen Ryan Wendell and Dan Connolly had down years, giving the Patriots coach an opening to bring in fresh bodies. Then there is the matter of the constant health issues between cornerback Aqib Talib, a free agent, and tight end Rob Gronkowski. New blood at both positions seem overdue for the sake of depth.

It’s going to be a long offseason. The team is only two and a half weeks into the process of mapping out how they will address the deficiencies on their roster. But we’re sure it won’t take long for them to determine who and what those deficiencies are.

Zuri Berry can be reached at zberry@boston.com. Follow him on Twitter @zuriberry and on Google+.