Pastore is said to be available for £25m, and the Argentinian reportedly impressed Mourinho during the Champions League games with Chelsea last season.
Pogba was recently spotted in London, fuelling talk of a move to Stamford Bridge, but agent Mino Raiola told Tuttosport that there have been no negotiations with Chelsea over his player's future and that he is happy in Italy.
"Paul to Chelsea? It's just fantasy football," Riola is quoted as saying by The Express. "Everything is perfect at Juventus and no meetings are planned."
Chelsea begin their Premier League campaign with a trip to new boys Burnley.