Middlesbrough midfielder George Boateng has been given permission to talk to other clubs about a possible move away from the Riverside.
The Holland international has been with Boro for six years but the 32-year-old has been talking to two other clubs after being frustrated by not being guaranteed a first-team spot.
Boateng has been linked with moves to Premier League new boys Hull City as well as Scottish champions Celtic.
Southgate told the club's official website: 'George has expressed a desire to move on.
'He's having talks with a couple of other clubs and that is the decision he has got to make now.'
Southgate explained Boateng had opted to look at his options after losing the captaincy meant he was no longer assured of his place.
Boateng was Middlesbrough skipper until January this year when he had the duties taken away from him by Southgate.
'He found himself disappointed at not being the first name on the team-sheet last season and I can understand that,' said Southgate.
'The way we worked in the past is that certain players were guaranteed their place on the team.
'George knows that if he is here, he will get a fair crack of the whip like everyone else.
'But he feels it would be better to move on. If he is totally committed he can stay.
'If not we'll shake hands and he can move on.'