Brown played nine seasons for the Steelers, while Foster is entering his 11th season with the franchise.
"Moving forward, any former player or affiliate of the Steelers who has an issue with anyone still in the locker room, please contact me or Maurkice Pouncey or anyone else you feel you can talk to," Foster wrote in his message Thursday. "Whoever you have an issue with, we will get you their number so you can address them. I promise."
"These media takes might give y'all good traffic on your social media outlets but the guys still in that locker room, who y'all still know personally, have to answer for those comments. Call them what you want, but call them personally and tell them. Defend who you want to defend but you don't have to mention the team at all."
"Whether you have a ring or played for one year ... enough ... chill. Most players at one point in their life want to take their kids back to the place where they once played, don't burn too many bridges. It's a long history or brotherhood more than anything. Business is one thing but let's keep it at a minimum for the guys who have to answer for those comments moving forward."
The Steelers do not face the Raiders during the 2019 regular season.