Chelsea transfer news: 'Medical' booked for £7.5m Premier League bargain as Xabi Alonso looks to evolve squad

Chelsea have reached an agreement with Aston Villa for goalkeeper Emiliano Martinez worth £7.5m, with a medical set to take place in London, the latest report has claimed.

The Blues began their Premier League season with a 3-2 win against local rivals Fulham on Monday, though the match was not comfortable viewing.

Boss Xabi Alonso will hope that his side are more defensively resilient over the coming weeks, but some of the club's issues may have to be addressed in the transfer window.

Shot-stopper Robert Sanchez made an avoidable error for Fulham's opener, and some supporters have called for him to be replaced.

BBC Sport claim that Chelsea have reached an agreement with Aston Villa for goalkeeper Martinez, with the deal set to cost the Blues back £7.5m.

Emiliano Martinez: Why Chelsea want Aston Villa goalkeeper

While Sanchez can add value to the Blues' squad, he has often been at the crime scene, with the shot-stopper regularly making errors between the posts.

The Spaniard's ball playing is strong, but there are serious question marks about his ability to reliably save shots, an area that Martinez has excelled in.

Having established himself as one of the best goalkeepers in the Premier League since the start of the decade, Martinez has proven to be good enough to win silverware.

Alsono has been on the lookout for more experienced players this summer, with Jordan Henderson and Danny Welbeck signed, so it comes as no surprise to see the 33-year-old goalkeeper targeted.

Emi Martinez latest: Should Xabi Alonso be worried about Villa goalkeeper?

While Martinez has won the World Cup with Argentina and played a key role in Villa's rise to the Champions League, the shot-stopper's performances last season were somewhat concerning.

The 33-year-old made uncharacteristic errors across the campaign, and there are fears that he has declined, and bringing him to Stamford Bridge may therefore be a risk.

Even if Martinez rediscovers his best form, Alonso should not rely on the Villa shot-stopper as a long-term option between the posts.