Gary Neville believes Chelsea's loss to Manchester United on Sunday shows they are crying out to strengthen their squad this summer.

Marcos Alonso withdrew from the contest after suffering an injury during the pre-match warm-up as the Blues suffered a 2-0 defeat at Old Trafford.

The Spaniard was replaced by Kurt Zouma in Antonio Conte's three-man defence with Cesar Azpilicueta moving to the left wing-back position, and Chelsea's poor showing without Alonso indicates to ex-United captain Neville that the West London outfit require some signings at season's.

"If they'd have lost Hazard and Costa and come here to lose I'd say fair enough," he said on Sky Sports.

"They've lost Alonso, are they that finely-tuned that they lose a left-back, he's a decent left back but he's not Roberto Carlos! And we're saying that basically they can just fall apart?

"It did imbalance them without the left-foot of Alonso, there is no doubt about that."

"A little bit worrying that it does though, one injury to your outfield player, that was the perfect Chelsea team apart from one player.

Neville added: "United had six or seven players missing, Liverpool had Lallana, Henderson, Mane out so every team misses players.

"So to think that one player missing would have that level of disturbance...

"It is disturbing moving forward, it is a glimpse moving forward for Chelsea if they are going to drop so far with one or two injuries, they do need to strengthen that squad."