Chelsea know that they have secured top four football with a game to spare in the Premier League and they can now have a real crack at trying to win the Europa League.

The Blues will be back in the Champions League next season and manager Maurizio Sarri could still end up with silverware too if they can overcome Eintracht Frankfurt in the Europa League semi-finals, before facing likely opponent Arsenal in the final.

(Photo by Emma Simpson/Everton FC via Getty Images)

But Sarri still has to make major improvements during his second year at Stamford Bridge, as Manchester City and Liverpool have been streaks ahead all season.

One area that Chelsea need to look at over the summer is at centre-back.

David Luiz, 32, is not the long-term solution for Sarri and his current deal expires in the summer.

Meanwhile, Andreas Christensen is still a developing talent that is getting plenty of first-team chances, but has room for improvement.

(Photo by Matthew Ashton – AMA/Getty Images)

Chelsea need to find a partner for Antonio Rudiger, who is the club’s most consistent performer in the heart of defence.

Kurt Zouma could be the perfect partner at centre-back next season and Chelsea should consider pairing him alongside Rudiger.

Zouma has enjoyed a season-long loan at Everton that has seen him earn regular minutes and get back to the kind of form he was showing before a serious knee injury.

(Photo by Chloe Knott – Danehouse/Getty Images)

The 24-year-old Frenchman is a powerful defender that reads the game well and has got the qualities to make a positive impact at Stamford Bridge.

He could form a physical partnership alongside Rudiger that would torment Premier League attackers.

Zouma cost the Blues £12million (BBC) and Rudiger cost £29million (BBC).