What's going on?

http://www.independent.co.uk/sport/football/transfers/anotine-griezmann-manchester-united-transfer-news-luke-shaw-memphis-depay-a7532356.html

"United will meanwhile be open to offers for Shaw. The 21-year-old has only made 13 appearances for the club this season, with none in the league since 29 October and none in any competition since the 30 November League Cup win over West Ham United."

"Mourinho is said to have become frustrated with Shaw's lack of progress in what the manager is trying to do with the team, and that has even led to some senior first-team players speaking to the young defender privately."

The part in bold I have a particular problem with. What the fuck does that even mean in this context?

A real shame. I hope the situation changes. What's happened?