The Vikings have agreed to terms with 16 undrafted college free agents, including Iowa quarterback James Vandenberg and three wide receivers. The players will participate in a rookie minicamp this weekend at Winter Park, and will be joined by about 30 more college free agents who are unsigned and trying out for the team. Vandenberg had a strong junior season, but struggled last year. He went from 25 touchdown passes in 2011 to seven in 2012. Vandenberg, who passed for more than 3,000 yards as a junior, is 6-3 and had the fourth-best overall score among 16 quarterbacks at the NFL combine in March. Wide receivers who will sign contracts, pending passing physicals, are Erik Highsmith of North Carolina, Nicholas Edwards of Eastern Washington and Rodney Smith of Florida State Highsmith, 6-3 and 190 pounds, had 54 receptions as a senior and 51 as a junior, scoring five touchdowns each season for the Tar Heels. Edwards (6-3, 200) had 95 receptions for 1,250 yards and 19 touchdowns in Eastern Washington’s high-powered offense as a junior, but those numbers dropped to 37 catches for 436 yards last year as teammate Brandon Kaufman set a Football Championship Subdivision record with 1,850 receiving yards on 93 catches. Smith, a 6-6 219-pounder, had 38 catches for 524 yards and three touchdowns. Also agreeing to terms were: • Defensive end Marquis Jackson of Portland State. Jackson (6-5, 260) is the twin brother of Denver Broncos defensive end Malik Jackson, who was drafted in the fifth round out of Tennessee last year. Marquis Jackson played at a junior college out of high school, then spent two years at Texas Southern before transferring to Portland State. • Safety Brandon Bishop of North Carolina State. A four-year starter, the 6-2 Bishop had 12 interceptions and 290 tackles during his college career. • Running back Bradley Randle of UNLV. Only 5-7 and 190 pounds, Randle was the backup to Tim Cornett and had 635 rushing yards and nine touchdowns as a junior. He declared for the draft early because he is graduating this spring.