Stricker won the 2020 French Open boys' singles title, defeating compatriot Leandro Riedi in the final.

He became the 3rd youngest Swiss player after Roger Federer and Stan Wawrinka to win an ATP Challenger title.

In June at the 2021 MercedesCup in Stuttgart he reached again the quarterfinals where he defeated second seed Hubert Hurkacz for his first top-20 win of the season.

He won his maiden ATP doubles title at the 2021 Swiss Open Gstaad, partnering Marc-Andrea Hüsler, defeating Polish pair Szymon Walków and Jan Zieliński.

In October, at the 2022 European Open in Antwerp, he defeated seventh seed Botic van de Zandschulp in straight sets in the first round as a qualifier.

[11] The following week, at the 2022 Swiss Indoors, he also reached the second round as a wildcard defeating Maxime Cressy[12] improving his chances to qualify for the 2022 Next Generation ATP Finals.

[13] He qualified for the 2022 Next Generation ATP Finals on 27 October 2022 and reached the semifinals undefeated beating top seed Lorenzo Musetti en route in a five set thriller lasting close to two hours and a half.

He won his first Major match at the 2023 Wimbledon Championships defeating Alexei Popyrin in five sets after qualifying for the main draw.

128, he reached the fourth round of a Major at the US Open after qualifying[19] and defeating again Alexei Popyrin, upsetting seventh seed Stefanos Tsitsipas in five sets[20] and Benjamin Bonzi also in five.

[21][22] He entered the 2023 Swiss Indoors as a wildcard and reached the quarterfinals defeating qualifier Benjamin Hassan and second seed Casper Ruud, his second top-10 win.