Chelsea boss Maurizio Sarri insists hat-trick hero Ruben Loftus-Cheek must sharpen up defensively to secure more Premier League football.

Blues midfielder Loftus-Cheek produced a match-winning performance during the 3-1 Europa League victory over BATE Borisov after being handed a rare Stamford Bridge start.

The England international has been restricted to just 33 minutes of league action since Sarri’s summer appointment.

Thursday evening’s treble showcased the 22-year-old’s undoubted attacking talent but his manager wants to see more from the player at the opposite end of the pitch and further tactical improvement if he is to be selected more regularly.

“He played very, very well – in the offensive phase, wonderful,” said Sarri.

“But in the beginning of the season, I thought he was really a very good player. Now I think the same but maybe I think also that he is more suitable to my football, he’s improving.

“I think also he needs to improve in the defensive phase. But not only Loftus.

“At the moment we have four midfielders for two positions and three of them with the same characteristics, three offensive midfielders.

“Only (N’Golo) Kante is a defensive midfielder, so it’s very difficult for me to put in the starting XI two offensive midfielders in the same time but I hope to be able do it in the future.

“I need the co-operation of the players, of course. I need an improvement in the defensive phase.

“I have a little problem, I have to put only 11 players in the starting XI and I have 28 players.

“I don’t know how to solve it. I can ask to play with 15, 16.”

In a week dominated by the fallout from Blues coach Marco Ianni provocatively celebrating in front of Manchester United manager Jose Mourinho during Saturday’s 2-2 draw, Sarri could not have hoped for a more straightforward victory.

Loftus-Cheek swept the Blues ahead inside two minutes with a first-time finish from Davide Zappacosta’s cut-back, before doubling the advantage six minutes later by volleying home Willian’s corner.

The former Crystal Palace loanee grabbed his third nine minutes into the second period, curling into the bottom right corner from the edge of the box via the fingertips of BATE goalkeeper Denis Scherbitski.

Marco Ianni was in the dugout following the controversy against Manchester United
Marco Ianni was in the dugout following the controversy against Manchester United (Nick Potts/PA)

It was the Blues’ first hat-trick in European competition since September 2006 when Didier Drogba’s treble earned a 3-1 Champions League win at Levski Sofia.

Aleksei Rios pulled one back for the visitors with 11 minutes to go but that could not prevent Chelsea taking a big step towards the knockout stages with a win which leaves them on maximum points from three Group L fixtures.

BATE coach Aleksei Baga said: “We were the participants of a very good game. We participated in a game with top players.

“We would like to have won today so at the end it was not a pleasant experience.”

BATE’s players wore black armbands in London following the recent death of club founder Anatoly Kapsky.

An emotional Baga added: “If I start talking about Anatoly Kapsky today, I’m afraid we’re going to miss our flight back home.

“Anatoly Kapsky meant everything to our club and everyone who experienced the loss of a very important person knows how difficult it is to discuss such a matter.”