NFL spokesman Corry Rush said Friday that Porter was fined for verbally abusing the opponent after the play was over.
Raiders defensive lineman Gerard Warren also was fined $5,000 for roughing the passer against Denver.
It has been a rough week for Porter, who on Wednesday apologized for not leaving the field as coach Tony Sparano ordered Sunday.
The Dolphins unraveled in the fourth quarter against the Patriots. Linebacker Channing Crowder was ejected for a scuffle with a New England player and Porter racked up two penalties.