Andre Villas-Boas says he will quit as Zenit St Petersburg coach at the end of the season in May after turning down a contract extension with the Russian champions.
The Portuguese coach won the Russian Premier League with Zenit last season in his first full campaign, but has not found life so easy second time around and is currently serving a six-game ban for striking a match official. Zenit are third in the table, six points behind the leaders CSKA Moscow.
The former Tottenham and Chelsea boss was linked with various European clubs, including AC Milan and Real Madrid, during the summer.
Villas-Boas told Zenit's official website: "The club made me an offer at the end of last season which I have refused and at the end of the season I will leave the club.
"But in any case we will continue to work hard, we need to score points, to catch up with those ahead of us, to try to perform successfully in the Champions League. The rules have changed and we will try to get out of the group stage and qualify.
"It is clear that we did not carry out any activity in the transfer market, which was expected, there wasn't a lot of choice out there, but anyway we tried our best, although it is obvious that no reinforcements came, except for those players that moved early in the transfer window."
Zenit have been paired with Valencia, Lyon and Gent in Group H of the Champions League.