West Ham are considering whether to sack Julen Lopetegui after Saturday's heavy defeat to Manchester City.
Hammers sources denied that Lopetegui had already been sacked, but accepted that the former Real Madrid and Spain coach is under great pressure.
Lopetegui (58 years old) was on the verge of dismissal before last month's match at home with Wolverhampton. But a win in that match sparked a four-game unbeaten run, West Ham's best run of the season.
However, a humiliating 5-0 defeat at home to Liverpool was followed by a 4-1 loss to Manchester City, leaving West Ham 14th in the table, seven points above the relegation zone.
West Ham manager Tim Steden has been pictured speaking to former Chelsea and Brighton boss Graham Potter, who was previously linked with the Hammers job.
The photo was circulated on social media. Sources said it was a recent photo, but this has not been independently verified.
Lopetegui was brought to West Ham in the summer, succeeding David Moyes, who left at the end of his contract. However, the former Wolves coach was unable to improve the team's performance or style, something for which Moyes was heavily criticized.
Club officials specifically confirmed that Steden would no longer work outside the club's training ground, in a move that echoes the split between Moyes and the former Bayer Leverkusen coach towards the end of last season.
West Ham sources said the decision is aimed at allowing Stetten to work on transfer targets for the current window. West Ham needs a striker after captain Jarrod Bowen suffered a broken foot and Michail Antonio suffered serious injuries in a car accident last month.
The club's next match will be against Aston Villa in the third round of the FA Cup on Friday. No clarity has been given on whether Lopetegui will be in charge of Villa Park.