The fifth-year player out of Georgia will be eligible to return Monday, Sept. 29, following the team's Week 4 game against the Raiders.
"The NFL recently informed me that I tested positive for a substance that is banned under the NFL performance enhancing substances policy," Jones said in a statement. "I worked closely with the union to investigate what happened, and I learned that a supplement I took caused the positive test. I deeply regret not investigating the supplement carefully before I took it, and I will never again take a supplement without having it checked. I am very sorry for the effect of my mistake on my teammates and coaches. I apologize to them, Stephen Ross, the Dolphins organization and fans. During the time away from the team, I will maintain an intense training program so that I can help my team as soon as I return."
Miami coach Joe Philbin added: "I was very disappointed when we found out about Reshad's suspension. When we talked to him, Reshad pledged to learn from this situation. Our secondary as a unit, including Reshad, has performed well this offseason and I have complete confidence in the group as we progress through training camp and into the regular season."
Jones, a starter who signed a four-year, $30 million deal last August and ranked 66th among all safeties last season (via ProFootballFocus.com), now joins 2013 first-round pick Dion Jordan on the bench. In July, Jordan was suspended four games for PEDs violation.