Johnson and the Lions faced the Atlanta Falcons on the road on September 7, 2008, in the season opener at the Georgia Dome.  As the official starting wide receiver behind Roy Williams, Johnson led the team in receptions and yards, collecting seven catches for 107 yards, which included one 38-yard catch-and-run in the Lions' 34–21 loss.  During Week 2 versus the Green Bay Packers, he had two key touchdowns late in the game, which sparked a large comeback, though the Lions eventually lost the game, 48–25. Both touchdowns catches included a run after the catch (the first catch going for 38 yards and the second going for 47 yards, both over the middle) displaying Johnson's speed and breakaway ability. He ended the game with six receptions for 129 yards and 2 touchdowns.  In the following two games, losses to San Francisco and Chicago, Johnson failed to score a touchdown or gain over 50 yards receiving.  However, against the Minnesota Vikings, Johnson had four receptions for 85 yards and his third touchdown of the season.