Sesko came off in the 88th minute of United's 2-2 draw with Tottenham Hotspur in the Premier League with what the club does not believe is a serious injury. United said he will continue to be assessed at their Carrington training complex this week.
Slovenia need to beat Kosovo on Saturday and then at least draw against Sweden away on November 18 to have any chance of a World Cup qualifying playoff spot, awarded to the team that finishes second in the group.
Slovenia are third in Group B with three points, trailing Switzerland (10) and Kosovo (seven). Sweden have one point.