“’Chilly’s not fit,” Lampard said. “We’re hoping Chilly might be okay for the last game or two of the season but that’s a tight call.
“It’s a similar story with Mason [Mount], maybe a little bit similar with Reece [James]. I feel like Reece might be slightly behind that. So we’re obviously chasing it a bit now.”
As well as England pair James and Chilwell, Chelsea are without Marc Cucurella for the visit of Forest, though Wesley Fofana is back available and on the bench.
The lack of options at full-back means 18-year-old Hall adds to his five Premier League appearances this season.
“Lewis has a chance,” Lampard said. “I’ve been really impressed with his training. He’s a very good player, a really talented player and if there’s one thing he needs to come out of himself that bit more and trust how good he is. He’s in the running for the last four games to be involved.”
Lampard also confirmed that Chelsea pulled Hall out of England’s squad for the upcoming Under-20 World Cup with a view to having him available for the first team.
“It’s my decision that he needs to stay with us for the four games,” Lampard said. “We’ve got injuries to both our left-backs who’ve been playing regularly this season and that leaves us in a position where we want and need Lewis.”
Mendy replaces Kepa Arrizabalaga in goal, while Joao Felix is handed a start up front, with Kai Havertz on the bench.
Starting XI: Mendy, Chalobah, Silva, Badiashile, Hall, Kovacic, Fernandez, Gallagher, Madueke, Felix, Sterling
Subs: Kepa, Pulisic, Loftus-Cheek, Mudryk, Ziyech, Fofana, Azpilicueta, Havertz, Fofana