The league will take no further action after the Port Adelaide forward contacted a teammate of Bulldogs opponent Bailey Dale.
It's an unwelcome distraction for the Power ahead of next Saturday night's Showdown against Adelaide.
"Port Adelaide is aware of a private message sent by Willie Rioli to a Western Bulldogs player following Saturday afternoon's game between the two clubs," the Power said in a statement on Monday evening.
"The matter has now been resolved privately after Willie contacted Bailey Dale from the Bulldogs."
The league also put out a brief statement, saying it had "reminded both clubs to ensure any communications remain respectful".
Port are coming off a 90-point thrashing from the Bulldogs on Saturday in Ballarat.
The text was sent after the match, which featured an on-field skirmish between Rioli and Dale.
Rioli can accept a $1000 fine for striking Dale off the ball in the third term.
Once the Bulldogs became aware of the text, they contacted the league and Port. The Bulldogs will head to Darwin to play Gold Coast on Saturday night.
Last month, Rioli posted on Instagram after Port's emotion-charged win over Hawthorn.
Rioli said he hated the Hawks, and the backlash prompted him to briefly take leave from the club.