Brown has missed much of Raiders' training camp after suffering a non-football foot injury.
Raiders wide receiver Antonio Brown will see a foot specialist, according to ESPN's Adam Schefter.
Brown has missed most of Oakland's training camp as he battles "sore feet" per ESPN. Brown the entirety of Raiders' practice on Thursday, Friday and Saturday.
No timetable has been set for Brown's return to the field.
"I think we're all disappointed," Raiders head coach Jon Gruden said on Saturday. "We think he's disappointed. We'd like to get the party started. We'd like to get him out here. He's a big part of the team."
Brown was traded to Oakland from Pittsburgh in March. The Central Michigan product has tallied 100-plus catches in six straight seasons, and he led the NFL with 15 touchdown catches in 2018.