Tottenham target Morgan Gibbs-White did not travel with the Nottingham Forest Squad for their training camp for the season in Portugal because of a private issue.
Sky Sports News has been told that the problem is not football or transfer related and was communicated internally by the midfielder.
Sky Sports News understands that the club likes to respect its privacy and Forest has not given a public comment about this.
It is expected that he will participate in the team later this week after his teammates landed on Faro Airport on Monday.
Nevertheless, it comes in a very difficult time for Gibbs-White and Forest, with relationships tense after the impasse with Tottenham about their £ 60 million bid for him.
Until now, the 25-year-old has continued to report for duty in accordance with his personal training plan, and there has been no indications that he will undertake a strike action or try to force a movement.
The stalemate continues between the two clubs about his proposed relocation to North Londen.
The Forest bosses closed the communication lines with Spurs and accused them of an illegal approach for the player and a violation of the confidentiality clause in his contract, which prevented any public release of the value of his buy-out clause.
Forest has made it clear in letters to both Tottenham and Gibbs-WHITE agent that they reserve the right to take legal steps in the future, and although Spurs remains interested in buying him and are willing to meet his £ 60 million clause, they have not yet pursued the case.