The Republic of Ireland international has been a rock at the back amid the club's spate of defensive injuries.
Clark, 25, started the season as the since-departed Paul Lambert’s fourth-choice centre-back behind captain Ron Vlaar, summer signing Philippe Senderos and Nathan Baker, with the Birmingham Mail even reporting that he could be loaned out.
Injuries to all three in November forced him into action alongside Jores Okore for the 1-1 home draw with Southampton, however, and the Republic of Ireland international hasn’t looked back since, starting all but two games on the backline.
His form even before Sherwood’s arrival was drawing widespread plaudits from the fans but, with three straight wins now on the board, the new boss is recognising just how crucial the former trainee is in their battle to avoid the drop.
“It's not easy when your partner keeps changing - we've had injuries there,” he said. "But Ciaran has always maintained his consistency. That's important for a defender.
"He's responsible and reliable."
In fact, Clark has become so crucial to Villa amid their spate of defensive injuries that Sherwood even opted to take him off in the 59th-minute of the 4-0 win at Sunderland for his own protection.
His withdrawal for midfielder Carlos Sanchez, who was forced to fill an unfamiliar centre-back role, had sparked some fitness fears but Sherwood actually wanted him to avoid a potential 10th booking of the season, which would have resulted in a two-game ban.
Asked about whether Clark’s withdrawal was fitness-related, Sherwood said: “No. I brought him off.
"He is on nine bookings. We needed to preserve him. You've got to think about these things."
It’s amazing to think that, after being on the first-team fringes at the start of the season, Clark has now became perhaps Villa’s most reliable defender, and his partnership with Okore could even keep Vlaar on the bench once the skipper recovers from his calf problem.
Out of contract in the summer, the veteran Dutchman looks to have been made expendable in the West Midlands now, which is a scenario few would have expected occurring following his starring World Cup performances in Brazil.