The 21-year-old returned from a season-long loan with the Foxes after Chelsea cut short his move to the Midlands.
Casedei had been playing regular football under Enzo Maresca, making 25 appearances in all competitions this term.
His loan spell was deemed a success so far, and Chelsea had been keen for him to remain.
However, Gazzetta dello Sport say Fernandez has been carrying a hernia problem in recent weeks and Chelsea want to bolster their options.
The Argentine missed the trip to Wolves on Christmas Eve with a hernia problem but he returned just a week later.
The World Cup winner, though, has not fully recovered and is playing through the pain barrier due to Chelsea’s lack of options.
Romeo Lavia missed the first four months of the season and then sustained a thigh injury on his debut for the club in December.
Casedei joined the club in a £12m deal from Inter Milan in 2022, with the move potentially rising to £16m.
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