Tottenham Hotspur boss Mauricio Pochettino says Kyle Walker will be back in the squad for the busy Christmas period.
The 24-year-old last featured for Spurs in March but played more than an hour for Tottenham's Under-21 side against Manchester City on Monday.
"All my staff went to see the [Under-21] game," Pochettino said.
"He played for 67 minutes and it was a very good first game. I am happy for him to play as it is different to training every day.
"It is not enough just yet but in the next few weeks he will be available to stay with the squad."
Spurs travel to Stamford Bridge on Wednesday to face leaders Chelsea with Pochettino describing Mourinho's team as the best in the Premier League.
"Costa is a very good player, I know him from Spain," the Argentine said.
"But if they don't play Costa they can play Didier Drogba or Loic Remy. These are different players, with different characteristics – but they are top players too.
"Chelsea are the best team in the Premier League at the moment, with an unbelievable squad. In the last 14 home games they've kept 11 clean sheets.
"But it's exciting to go and play there, in a difficult stadium, and try to get three points."
