Chelsea's title-winning manager Antonio Conte has benefited from the work of his predecessor at Stamford Bridge - Jose Mourinho, according to Gary Neville.

Conte has transformed the Blues from a team bereft of confidence into the Premier League champions in only his first season in charge of the west London club.

However, Neville believes the Italian owes a great deal to Manchester United boss Mourinho, who led Chelsea to three league titles over two separate spells.

Chelsea boss Antonio Conte owes a great deal to Jose Mourinho, according to Gary Neville

Neville says Conte and Carlo Ancelotti both benefited from Chelsea teams that Mourinho built

'I think ultimately Jose has built two great sides at Chelsea,' Neville told Sky Sports, ahead of Chelsea's match with Watford on Monday night.

'[Carlo] Ancelotti and Conte have profited - managed them brilliantly - but profited off the back of those two championship-winning teams.'

Neville has been impressed with Conte's impact at Stamford Bridge but expects the Italian's second season to be a much sterner test for a number of reasons.

'I think there are three big challenges moving forward for Conte and Chelsea next season,' Neville said.

Mourinho won three Premier League titles during two separate spells at Stamford Bridge

'The first is a physical one. Those eight, ten, twelve matches less. Make no mistake about it, that's an incredibly big advantage when you play less football.

'You have more time to prepare, to recover. It's a big advantage against other teams that are in Europe.

'When you're not in the Champions League or Europa League you have a huge advantage, so the biggest challenge moving forward is physicality.

'[The] second challenge is mental. These players are the same players who have let Chelsea down before. They've climbed the mountain and can't get themselves up for next season.

The Portuguese was sacked midway through the 2015-16 season with the Blues struggling

'I can't imagine that they're going to drop to tenth next season but Antonio Conte's big job is re-motivating those players.'

Neville also fears for the Blues, should they lose top scorer Diego Costa during the summer window.

The Spain international has been linked with a big-money move to the Chinese Super League or a return to Spain but Neville says the newly-crowned champions must do all they can to keep the former Atletico Madrid man.

Neville says Chelsea must do all they can to stop Diego Costa leaving the club this summer

'Costa, for me, is an animal,' said Neville. 'When he's not scoring, he's contributing. The way Chelsea play, with a single striker, if he leaves it's a huge void to fill.

'Forget the fact that you might be able to get somebody who scored the goals he scored, which is a challenge in itself, but to replace that personality, that fire, [will be hard].'

However, Neville's Monday Night Football colleague Jamie Carragher says Chelsea have a history of coping with high-profile departures from the club.

Jamie Carragher expects the Blues to recover if Costa leaves during the summer window

'Don't forget that spine that we felt, without them, they couldn't win – Cech, Terry, Lampard, Drogba,' Carragher said.

'They've won two leagues without Frank Lampard and Didier Drogba, Petr Cech's moved on – they've won two without him. John Terry hasn't played this season.

'That's what I'm talking about – that winning mentality going through the club. Without Costa you would still back that club to find a way to win.'