Chelsea already have a fantastic defence ahead of the new Premier League season, but the addition of Mehdi Benatia would make the Blues back line even better.
Manager Jose Mourinho is reportedly interested in signing up the highly rated Roma centre-back despite the presence of Gary Cahill, Branislav Ivanovic and John Terry in his squad.
Chelsea sold David Luiz to Paris St-Germain earlier in the summer for £50 million, and Mourinho is reportedly looking to Moroccan international Benatia as a replacement, having missed out on Real Madrid's Raphael Varane, per David Woods in the Daily Star:
Chelsea are set to land £30m Roma central defender Mehdi Benatia. Boss Jose Mourinho wants to strengthen his defence with a move for highly-rated French-born Moroccan international. Benatia, 27, is also being chased by Manchester United, but Chelsea are ready to seal the deal this week ahead of their first game at Burnley on Monday.
As Woods points out, the French-born player is much sought-after, and it would be a major coup for Chelsea if they could snap him up.
Furthermore, Roma boss Rudi Garcia is seemingly convinced that Benatia will continue in the Italian capital, per Football Italia.
"As far as I can see he has a four-year contract and that's all that needs to be said."
With Chelsea looking to compete on domestic and European fronts next season, they need strength in all areas of the field.
With Terry getting on in years, he will not be able to play every game, and the addition of Benatia would bring real depth to the central defence, with versatility also on show as Ivanovic often plays out on the right.
Mourinho's sides are often defined by their frugality in conceding goals. When he won his first Premier League title in 2004-05, the Blues conceded just 15 all season.
The addition of Benatia would all but ensure that—no matter the situation—Chelsea have a solid defence in the new season.
He was part of Serie A's second-meanest defence last season, and as far as beIN Sports' Matteo Bonetti is concerned, he was the best defender in the division:
Mourinho would not be buying a back-up in purchasing Benatia; he would be buying one of the world's best defenders who would challenge the established duo of Cahill and Terry for their starting spots, thus improving the side overall.
Furthermore, he would be a huge upgrade on the departed Luiz, who was something of a liability in terms of genuine defensive ability.
While the Brazilian was excellent at playing the ball out from the defence, his reliability was suspect—an inconsistency not evident in Benatia's play. The Roma man also offers the odd goal, having scored five in the league last season.
At the price being reported, Benatia would represent an expensive purchase, but not ludicrously so. He is a very high-quality centre-back who would add real strength to Chelsea's ranks and provide competition, which would likely improve those around him.
Furthermore, Mourinho's side would be genuinely set to compete on all fronts, as they would have a back line which even the best attacks would struggle against.