Marco van Ginkel has extended his contract with Chelsea - and rejoined PSV Eindhoven on loan on the same day.
The 24-year-old Netherlands midfielder, who signed for Chelsea in 2013, has extended his deal by a year to 2019.
He helped PSV win the Dutch title while on loan during the second half of the 2015-16 campaign and will now return to Eindhoven until the end of this season.
In recent months he has had treatment for a recurring knee injury but said he is "now ready for top football".
"Rest and physiotherapy were necessary," Van Ginkel said.