He began his career at a club in Mosina[1] before coming through the ranks at Warta Poznań. He spent his career at Warta until February 2019, when he moved to Elana Toruń. He then went on to play half-a-season with Polonia Środa Wielkopolska in 2020 before joining Lech Poznań's reserve team on 6 February 2021.[2] As an experienced player, his role was to help and mentor the youth and work towards a coaching licence.[3]
Illness
In June 2021, Onsorge fell gravely ill and underwent a head MRI scan; he was subsequently diagnosed with an inoperable[4]brain tumour,[5] specifically in the parietal lobe.[6] In order to help fight the life-threatening situation, a fundraiser for his medical costs was started, promoted by both Poznań clubs and the people associated with them.[7] In late 2022, he announced that his recovery was going well.[8]
