The deep-lying midfielder was a flagship signing for Maurizio Sarri at the start of his Stamford Bridge reign, having been heavily linked with a move to Manchester City before ending up in London.
However, Jorginho's performances have come under increasing scrutiny as the Blues have faded after a strong start, leaving them in a battle to secure a top-four finish.
A section of fans at Stamford Bridge cheered his substitution during the recent 1-1 draw against Wolves – Jorginho being selected at the base of the midfield instead of N'Golo Kante has become a considerable bone of contention - and Sarri's men lie sixth in the table following Sunday's 2-0 loss at Everton.
Jorginho has now joined up with Italy for their opening Euro 2020 qualifiers against Finland and Liechtenstein and Mancini has no doubt that he has a high-quality performer at his disposal.
"Jorginho is playing very well. He hardly misses any games," he told a news conference.
"Chelsea aren't doing as well as usual but he has great quality, like [international team-mate Marco] Verratti, who is key for PSG in midfield."
Chelsea are through to the quarter-finals of the Europa League alongside Arsenal, with four Premier League representatives making up half of the last eight in the Champions League.
Juventus are flying the flag for Italy in the latter competition, while Jorginho's old club Napoli are among the favourites for Europa glory.
"Juventus are still strong, they played a great game [against Atletico Madrid] it was not easy to overturn that result there," Mancini added, before acknowledging the boost that club continental success could have as he continues to rebuild a national team that failed to reach the 2018 World Cup.
"Napoli have what it takes to win the Europa League. In the end there are two winners and we hope they are the Italians."