The West Midlands outfit are currently participating in their first-ever campaign where they have had to combine Premier League and Champions League football.
Generally-speaking, Emery and his squad can be satisfied with their efforts, sitting in ninth position in the Premier League table and eighth in the Champions League standings.
However, Emery witnessed his team put together a five-game winless streak before the November international break, something that could realistically have put doubt in his mind over members of his squad.
Most notably, Villa are currently on a run of five halves of football without a goal, yet it appears that Emery is more concerned regarding his defensive options.
Villa has doubts over defender?
According to Football Insider, Emery no longer views Diego Carlos as a defender who he views as a key part of the squad.
The 31-year-old has made a total of eight starts and three substitute outings in all competitions during 2024-25, his presence required with Villa having been waiting for Tyrone Mings to fully recover from a serious knee injury.
There have been times when Carlos has been a star performer, helping Villa keep clean sheets against the likes of Bayern Munich, Manchester United and Bologna.
On the flip side, the Brazilian was less than impressive against the likes of Ipswich Town and Tottenham Hotspur, adding to the perception that he may soon become a bit-part player in Emery's squad.
Therefore, Carlos, who possesses a contract until 2026, may now be made available for transfer at the midway point of the campaign.
Replacement already identified?
Emery may be of the opinion that Mings can now start more matches having come through two appearances with no ill-effects from an injury that kept him sidelined for 14 months.
Nevertheless, a report last week suggested that Real Betis centre-back Diego Llorente had been identified as a potential signing ahead of January.
That is despite the former Leeds United man having only recently moved to the La Liga side, where he has impressed and holds a four-year contract.
Much may depend on what level of interest that Carlos attracts. Fulham have been credited with an interest in the past, while clubs on the continent are likely to be admirers given his previous success at Sevilla.