MINNEAPOLIS — The Minnesota Vikings have spent about a year sending gifted but flighty receiver and kick returner Cordarrelle Patterson messages that he needs to buckle down and come to training camp prepared to earn a spot.

They sent their loudest message yet on Monday.

The Vikings declined to pick up the fifth-year option on Patterson’s rookie contract, casting his future with the team into doubt.

On the same day the Vikings exercised the options for defensive tackle Sharrif Floyd and cornerback Xavier Rhodes — the other two members of the Vikings first-round class in 2013 — the team preferred not to commit to the $7.9 million Patterson would have been due in 2017.

The Vikings also signed sixth-round draft choice Moritz Boehringer to his rookie deal, making him the first pick of the 2016 class to sign a contract. The team also announced the signing of 10 undrafted free agents, including two area prospects: Minnesota defensive end Theiren Cockran and Wisconsin quarterback Joel Stave.

Patterson was an All-Pro kick returner as a rookie and has continued to be a threat in that spot in his first three seasons in the league. But his development as a receiver has been much slower to come. He only caught two passes last season and was used as a decoy or blocker in the few offensive snaps he did get.

The 22-year-old Boehringer is from Germany, making him the first player in league history to be drafted straight from Europe.