Minnesota Vikings On April 27, 2013, Line signed with the
Minnesota Vikings as an
undrafted free agent following the
2013 NFL draft. In the Vikings' first preseason game against the
Houston Texans, he scored on a 61-yard touchdown pass from quarterback
Matt Cassel. In the season opener against the
Detroit Lions, he had one reception for eight yards in his NFL debut. He appeared in two other games in the 2013 season. Line was released by the team on September 14, 2014, re-signed to the practice squad shortly after, then was promoted to the active roster on October 3. On September 20, 2015, Line scored the first touchdown of his career against the
Detroit Lions. The next week, against the
San Diego Chargers, Line scored another touchdown, the second of his career. Line also caught a pass from quarterback
Teddy Bridgewater and took it 49 yards to set up a score in Minnesota's 28–19 victory over the Detroit Lions in Week 7. Overall, in the 2015 season, he finished with six carries for ten rushing yards and two rushing touchdowns to go along with six receptions for 95 receiving yards and one receiving touchdown. In the 2016 season, he finished with seven carries for 15 rushing yards in 15 games.
New Orleans Saints On August 24, 2017, Line signed with the
New Orleans Saints. He was released by New Orleans on September 2. Line was re-signed by the Saints on October 3. In 12 games, he finished with seven carries for 28 rushing yards to go along with two receptions for eight yards and a receiving touchdown. The Saints made the playoffs and faced off against the
Carolina Panthers in the
Wild Card Round. In the 31–26 victory, he had a one-yard rushing touchdown. Line and the Saints' season ended in the Divisional Round in a
29–24 loss to the
Minnesota Vikings. On April 5, 2018, Line re-signed with the Saints on a two-year contract. In Week 3 against the
Atlanta Falcons, Line scored his first touchdown on the season. He finished the 2018 season with nine carries for 41 rushing yards to go along with five receptions for 14 receiving yards and two receiving touchdowns. In the 2019 season, Line appeared in 12 games and recorded seven carries for 20 rushing yards to go along with six receptions for 36 receiving yards. On January 15, 2020, Line announced his retirement from the NFL via Instagram after seven seasons at the age of 29. Line finished his career with 36 rushing attempts for 114 yards and two touchdowns and caught 20 receptions for 161 yards and four touchdowns. Line returned five kickoffs for 59 yards and recorded seven special teams tackles over the span of his career playing on
special teams. ==Coaching career==