[1][2][3][4][5] Sigren began playing rugby at school before joining local Santiago side Old Boys Club.
[6] He joined Chilean franchise Selknam in 2019 for the inaugural Superliga Americana de Rugby however only made one appearance with the season being cut short due to the COVID-19 pandemic.
In August 2022 he signed a one year long contract with English Championship side Doncaster Knights where he became the first Chilean to play professional rugby in England.
[7][8] After the 2023 Rugby World Cup he joined American MLR side New England Free Jacks.
[11] He has also featured for Chile XV captaining them in the Sudamericano Cuatro Naciones[es] as well as a match against URC side Leinster.