Ricardo returns to the side after being rested against Slavia Prague due to the length of time that he was unavailable beforehand, while Castagne comes back into contention after recovering from a hamstring injury sustained against Leeds United.
The Foxes have struggled in terms of injuries defensively all season and after losing James Justin to a lengthy spell on the sidelines, all of their senior full-backs have been unavailable at one point or another during the season.
It would be unlikely that both of them complete the full 90 minutes, with Castagne especially only just returning to fitness, but will Brendan Rodgers elect to give them both the nod from the start?
Start them both in a back four
Leicester have found success playing in a 4-2-3-1 formation with Wilfred Ndidi and Youri Tielemans playing deep while the likes of Harvey Barnes, James Maddison, Marc Albrighton and Jamie Vardy look to cause trouble in an attacking sense.
Due to the way this formation is set up, there is less of an emphasis on the full-backs to get forward to provide width due to the likes of Barnes and Albrighton already doing so, meaning Ricardo and Castagne have the chance to conserve their energy in a bid to avoid further damage.
This formation also gives the pair license to join in attacks thanks to the deep-lying Ndidi and Tielemans who would be available to provide cover in defensive areas. This means that while they would look to track back should Villa counter, the likes of Ndidi can slot into the defence and Caglar Soyuncu and Jonny Evans can split to cover the flanks that have been vacated.
This formation may also be utilised in a bid to stop the creativity of Jack Grealish as the winger, most likely Albrighton, and full-back can double up on the England international to try and starve his attacking threat.
Start them as wing-backs
Leicester have the personnel to set up in a defensive three with wing-backs, with Soyuncu, Evans and Daniel Amartey lining up across the back. They can then utilise Ndidi and Tielemans in midfield with Maddison slightly ahead of the them and Vardy and Barnes in attack looking to run in behind.
This narrow formation invites the wing-backs to provide the width that is lost with the lack of wingers and may play to Ricardo and Castagne's strengths as they both thrive in attack.
The question marks surrounding this formation are that both wing-backs have to be able to get up and down the pitch for the full duration that they play, something that Castagne must be wary of especially after having just recovered from a hamstring problem.
There is no doubting that both players would suit the shape as both provide excellent support in attack, but their fitness levels may not be up to the required standard and should they play this formation, there will be an emphasis on the back three to cover them should they not be able to get back into their defensive positions.
Taking a cautious approach
It is highly likely that both Ricardo and Castagne will both feature in the game against Villa, though Rodgers may think against starting them both.
Ricardo should get the nod as he was only rested as a precaution and has built himself up to fitness, but Castagne has been unavailable for a month and in both a crucial and busy period for the Foxes, Rodgers may want to introduce him off the bench in order to build him up slowly and avoid any more injuries, especially after losing Justin for the season.
The Foxes have utilised the pairings of Amartey and Ricardo against Liverpool and Amartey and Luke Thomas against Slavia Prague, but with Slavia coming up once again soon after the Villa clash and Arsenal to follow, Rodgers faces a game of chess with his players in a bid to keep them all fit and firing.