Gruszecki signed with Spirou Charleroi in Belgium for the 2013–14 season.[1] He finished the season in his home country of Poland, on loan with Czarni Słupsk. For the next season, Gruszecki signed a full contract with Czarni Słupsk. After the 2014–15 season, he was named to the All-PLK First Team.[2] He also finished as runner-up in the voting for Best Polish Player.[3] He signed with reigning PLK champion and EuroLeague team Stelmet Zielona Góra in the 2015 offseason. He played with them for two seasons before signing with Pierniki Toruń.