Drafted 98th overall by the Ducks in the 2000 NHL Entry Draft from Swedish side Luleå HF, Rönnqvist played 38 regular season games during the 2000–01 NHL season, scoring four assists and collecting 14 penalty minutes. After spending the entirety of the 2001–02 season with the Ducks' AHL affiliate the Cincinnati Mighty Ducks, Rönnqvist returned to Luleå where he remained until his retirement in 2005, caused by an injury.