Vikings on the bubble: Four players on the roster bubble entering training camp

Last year, Alex Boone was the veteran who got the last-second cut. The guard refused a pay cut and the Vikings released him after he'd already started to lose his starting job in training camp. Which veterans are on the bubble this summer?

NFL season: ninth

2018 guarantee: $500,000

Sherels gets the annual dishonor of media questioning his security with the Vikings, just like this. Forgive the previous transgressions, Marcus. But this time, the 30-year-old's extension was less lucrative — $500,000 guaranteed for one year, down from $1.5 million on 2016's two-year deal — and the Vikings drafted a dynamic college returner in first-round pick Mike Hughes, also a cornerback.

NFL season: seventh

2018 guarantee: $100,000

The Vikings re-signed Forbath, who has made 50 of his 57 field-goal attemps in two seasons with Minnesota, about six weeks before trading up to draft Daniel Carlson in the fifth round. Forbath's one-year deal included a $100,000 signing bonus. Otherwise, he has no guaranteed money from the Vikings. The 30-year-old veteran, who also has missed eight extra points in 25 games, will need a stellar camp to hold off Carlson.

2018 guarantee: None

Robison, 35, took a pay cut trimming two-thirds of his salary for his final season under contract. Robison should make the roster as a rotational end and leader in the locker room for what he expects to be his last NFL season. However, his contract, age and the Vikings' young talent at defensive end could lead to discussion should Stephen Weatherly, Tashawn Bower, Ifeadi Odenigbo and/or Ade Aruna have strong summers.

NFL season: fourth

2018 guarantee: None

Bell, a former 2015 fourth-round pick, played 145 snaps last season and would have played more if not for season-ending shoulder surgery in December. The former Oklahoma QB, 26, enters a camp competition for the No. 3 spot with fifth-round pick Tyler Conklin.