New deal with 23-year-old midfielder runs till the end of 2023/24 season.

Omsk native Mostovoy joined Zenit in February 2019 from FC Khimki. He spent the second part of 2018/19 season with the second team in FNL, and for the next year Zenit loaned the player to RPL newcomers FC Sochi. Mostovoy scored six goals in 25 league games for Southern club.

After his loan expired the midfielder came back to St. Petersburg and repeated his result of six RPL goals in 25 games with winning the Russian Super Cup and RPL Championship for the first time in his career.