Massimiliano Allegri says there is no questioning the "extraordinary" Paulo Dybala's value to Juventus and does not expect Arthur to leave this month.
Dybala's future is in doubt as the Argentina forward's contract expires at the end of the season and the 28-year-old has been linked with a move to Serie A rivals Inter.
Juve director Maurizio Arrivabene this week called for Dybala and his team-mates to show "character, grit and a desire to win" as the Turin giants battle for a Champions League spot.
Bianconeri head coach Allegri, who will take charge of the club for a 300th time when they face Udinese in Serie A on Saturday, says Dybala still has a big part to play.
He said: "The evaluations of the contracts are the job of the company, they are not things that concern me.
"I raised Dybala, he was a child when he arrived from Palermo, now he's grown up and he's an extraordinary player. I expect a lot [from Dybala] in this second part of the season. The value of the player is not discussed. He is a great player "
He added: "We are in a situation where we are temporarily out of the Champions League, so all the evaluations will be done in March/April. Juventus plans like this and we have to think about playing and working, we will see the rest later."
Midfielder Arthur has been strongly linked with a move to Premier League side Arsenal during the January transfer window.
Allegri is not planning for life without the Brazilian and also reiterated that Alvaro Morata will not be departing.
He said: "I don’t want to repeat myself. We have to get to the end of the season with these players in the best possible way.
"This means trying to reach the top four and go ahead in the Champions League and Coppa Italia."
Italy centre-back Leonardo Bonucci will miss Udinese's visit to Allianz Stadium due to a muscle injury.