Zenit St Petersburg have sacked coach Luciano Spalletti with the club lying second in the Russian Premier League.
Chris Powell has been sacked by Championship strugglers Charlton less than a week after agreeing a new deal.
Stoke have completed the signing of England international goalkeeper Jack Butland from Birmingham.
The npower Championship club accepted an undisclosed fee from the Potters for the 19-year-old, with the keeper set to stay at Birmingham on loan until the end of the season.
Butland had earlier rejected talks with Chelsea because of his desire to play regular first-team football and had also been linked with Liverpool, Fulham, Newcastle and Manchester City in this window.