Ellerbe believes the Patriots are vulnerable after the free-agent defection of Wes Welker, multiple surgeries to star tight end Rob Gronkowski and the release of tight end Aaron Hernandez, who is currently jailed on a murder charge.
"I was brought here to help knock them off," Ellerbe, who signed a $35 million, five-year contract with Miami this offseason, told CBSSports.com. "That doesn't mean we will, but we feel like we can."
Ellerbe, who helped the Ravens beat the Patriots in last season's AFC Championship Game with five tackles and a key fourth-quarter interception, told the website that Baltimore's approach to the Patriots was "to keep fighting" and "eventually we could get inside their heads."
The linebacker said the loss of Hernandez, who was released by the Patriots less than two hours after his arrest last month for the murder of 27-year-old Odin Lloyd, particularly hurts the Patriots.
"Losing a starter always hurts and losing a starter as good as he was will really hurt," he told the website.
The Patriots, who have won four straight AFC East titles, finished five games ahead of Miami in the division last season. The Dolphins, however, are hoping to narrow the gap behind the development of second-year quarterback Ryan Tannehill and a big-spending period during free agency, highlighted by the additions of wide receiver Mike Wallace and Ellerbe.
Information from ESPNBoston.com's Field Yates was used in this report.