Cardiff City have given captain David Marshall permission to discuss personal terms with Premier League club Hull City following their £5m bid for the Scotland goalkeeper.
The 31-year-old has been left out of Cardiff's squad for Saturday's Championship match against Reading.
Marshall has made more than 280 appearances for Cardiff since arriving from Norwich City for free in 2009.
Cardiff have signed Bolton goalkeeper Ben Amos on a season-long loan.
However, they have also sold back-up keeper Simon Moore to Sheffield United.
Marshall, considered one of the best goalkeepers outside the Premier League, was the subject of interest from West Bromwich Albion last summer and has also been linked with Everton.