The duo was included in the Blues’ 21-man squad for Thursday’s Round of 16 first-leg fixture, with manager Enzo Maresca confirming their readiness to play.
Badiashile has been sidelined since December 2024, while Chalobah was ruled out for the Southampton match due to an injury picked up against Aston Villa.
"They are both ready," Maresca told Chelsea website during Wednesday’s pre-match press conference.
"Trev, fortunately for us, was not something serious, so he is ok. Benoit is back and has been training with us in the last ten days, maybe even more.
"Wes is not in the squad but is back. Romeo started to train with us in the last two days. So slowly, slowly we have all the players back which is important for the final rush of the season."
After finishing atop the league phase, the Stamford Bridge giants aim to advance to the next round but must first navigate a two-legged battle against the Danish powerhouse.