Everton manager Roberto Martinez has admitted that the defensive reunion of Phil Jagielka and John Stones has been key in the club's return to form in the Premier League.

Since Stones regained his place in the starting lineup, the Toffees haven't lost in six games, and Martinez has revealed that he is delighted with the development of what he describes as a "natural partnership".

The 41-year-old told Everton.tv: "They complement each other really well and the most important reason is that they are phenomenal footballers.

"In Phil Jagielka, you have got a captain, a leader and someone who is probably enjoying the best football of his career.

"He has that chemistry and understanding with someone so talented like John Stones. It is a joy to see John developing and growing as a footballer. To see him doing it alongside Phil, it is a very natural partnership and it has been really effective for us."

Both men are expected to start when Everton travel to Aston Villa on Saturday afternoon.