Manchester City manager Pep Guardiola says he has not lost faith in England centre-back John Stones and has no plans to replace him with Southampton's Dutch defender Virgil van Dijk.

City and Premier League leaders Chelsea have been linked with Van Dijk despite Southampton's insistence the highly regarded centre-back is not for sale.

Stones, 22, has struggled since his £47.5 million ($59.3 million, 56.8 million euros) switch from Everton and has spent City's last two games on the bench, but Guardiola said he was merely being rested.

"It's the first time in his career he played every three days," Guardiola said. "It had never happened before with the Champions League and the League Cup and every three days you have to be focused.

"He played a lot. If I didn't have confidence in him, he would not have played the games that he played.

"Of course he must improve, like (Nicolas) Otamendi must improve, like (Aleksandar) Kolarov must improve and like Vincent (Kompany) is coming back (from injury).

"I decided to play with a back four against Watford (a 2-0 win) for some reason and I tried the same back four for the Arsenal game (a 2-1 win).

"I know that people think if a player doesn't play it is because the coach doesn't trust him anymore. That is not the truth.

"Our job is uncomfortable. It is unfair in most of the cases of many, many players because they deserve to play, but I cannot find a solution for these kind of things.

"All of them have to prepare because it is so long and now we start a tough moment and immediately arrive in the (FA) Cup and the Champions League and everybody has to be prepared."

Guardiola also believes that, despite his tender years, Stones has the strength of character and personality to cope.

- Full-back vacancy -
"He's young, he has to improve, but he's open and he has a lot of personality," said Guardiola.

"When you play in the big teams, the character is there. All the big clubs buy huge players.

"I am not able to say the players from Chelsea, (Manchester) United, Arsenal, Tottenham -- all of them have quality.

"The difference is the personality, how they react in the bad moments. John is one of them, I don't have doubts about that."

Guardiola, further, insisted Van Dijk will not be on his way to the Etihad Stadium in the new year.

While the City manager does not necessarily expect a new signing at the club in the January transfer window, he refused to rule out a potential move for a full-back.

"Will Van Dijk come here? Next month here? We are going to Southampton to play against them. He is not going to come here next month, because it is impossible," laughed Guardiola.

"Because he is a Southampton player and we don't want him now. We are going to go to Southampton to play them, that's for sure.

"I said before that if you ask me today, 'No.' But maybe next week if we decide to change and we realise maybe we need something special maybe in one position, one more player in that position because we don't have too much, especially in the full-backs.

"But the other positions we are quite happy."