Free agent Brown signed a $3.5m (£2.1m) deal with the Oakland Raiders this week, having left the 49ers after seven years with them.
Following his transfer, he told NBC Sports: "It wasn't what I wanted and it was to me more of a slap in the face. I understand that it's a business and I understand that they have to do what is best for them and it's no hard feelings.
"But what they offered me definitely wasn't what I wanted and definitely wasn't worth my value of what I've done in this league and how well I played these past 3-4 years in the league. It's understandable and like I said there's never any hard feelings.
"They are doing a great job over there and I wish them the best."
By not participating in the 49ers' off-season workout program last summer, Brown lost $2m (£1.2m) in base salary and was hopeful that the team would make up for it in their offers this season.