Brown debuted at Raiders camp in Napa, Calif., Friday morning. The Raiders acquired Brown in an off-season with the Pittsburgh Steelers.
Raiders coach Jon Gruden joked he expected more from Brown.
"I thought he might jump out of an airplane and parachute himself in," Gruden told reporters Friday.
Brown has 837 career receptions for 11,207 yards and 79 touchdowns since debuting in 2010. Brown played his entire career for the Steelers.
Brown caught 104 passes for 1,297 yards and a career-high 15 touchdowns last year.
"He's going to add a lot of life to this organization at a position where obviously we need some explosive plays," Gruden said.