Nemanja Matic
Nemanja Matic has been a key player for Chelsea this seasonReuters

Chelsea midfielder Nemanja Matic is reportedly set to sign a lucrative five-year deal worth around £4.8 million-a-year.

The 26-year-old, who returned to Stamford Bridge for a second spell from Benfica for a transfer fee of £21 million in January 2014, has been one of the main reasons behind the Blues' excellent form this season, forming a solid partnership with Cesc Fabregas in the central/defensive midfield.

And now, the Daily Express claims that Chelsea are going to reward the Serbian with a new five-year deal worth around £93,000-a-week after taxes. It is believed that the news will be officially announced in the next couple of days.

His importance to the Chelsea squad, who are right on course to win their first Premier League title since the 2009/10 season, was highlighted when Blues manager Jose Mourinho fought tooth and nail to reduce the midfielder's ban, which resulted after Matic angrily reacted to a horrendous tackle from Burnley's Ashley Barnes.

The FA eventually reduced the ban from three to two games, but Chelsea still publicly expressed their disappointment as Matic missed the Blues' Capital One Cup final and Premier League clash against Tottenham and West Ham United respectively.

Meanwhile, Mourinho revealed after his side's Premier League triumph at West Ham United that Matic had hurt his ankle while celebrating Chelsea's success against Tottenham Hotspur in the finals of the Capital One Cup with the rest of his teammates.

Although the Portuguese admitted that Matic would not have played at West Ham if he was not suspended, he insists that the injury is not serious and the former Benfica man will be available for the Blues Champions League clash against PSG on Thursday.

"Matic got an injury celebrating the cup. It's not a big injury, but if today he was not suspended, he wouldn't play," Mourinho told Sky Sports.

"He twisted his ankle. On the pitch. He put on shinpads but he didn't put the tape on. He will play against Paris. On Saturday, Sunday, he will train."