[2][3][4] In mid-2016, on the back of reaching a junior French Open quarterfinal, then-15-year-old Iga Świątek began working with Sierzputowski, then 23, at Legia Warsaw.

[2] When Świątek began playing main WTA Tour events in 2019, Sierzputowski formed her core travel team along with sports psychologist Daria Abramowicz and eventually fitness trainer Maciej Ryszczuk.

[2][5][6][7] Świątek was quickly successful on the WTA Tour—in 2020, she made a surprise run at the French Open to claim her first major title, at age 19.

[8] However, in the off-season before 2022, she and Sierzputowski split amicably due to "burnout" after six years together, wishing each other well on social media; he was replaced by Tomasz Wiktorowski.

[9][10][11] In early 2022, Sierzputowski began working as a tennis commentator on Eurosport Polska, including for some of Świątek's matches.