Vlaar, 30, has featured just 14 times for Villa this season due to injuries and suspension, with his latest appearance coming in last month’s 2-1 defeat to Stoke, when he was sent off after conceding a last-gasp spot-kick.
Both Philippe Senderos and Nathan Baker have also been sidelined in recent months, leaving the since-departed Paul Lambert and now Tim Sherwood with a serious shortage of central defensive options.
However, Clark and Okore, who started the season as fourth and fifth-choice centre-backs, have struck up a superb rapport in the meantime and Vlaar has been delighted to see them performing so well, picking out the former for particular praise.
“It’s really good to see. If you look back to the start of the season, Jores was coming back from a big knee injury and Ciaran wasn’t involved in most of the games,” said the Dutchman.
“Now they’re both playing in every game and that shows great mental strength. If I had to pick one out, they’re both playing really well, but Ciaran has been really good.
“He’s a leader who’s really stepping up and I’m really glad to see that. That’s good for the team, good for him and good for everyone.”
Out of contract in the summer, there’s a strong argument to make that the form of both Clark and Okore has even made Vlaar expendable at Villa Park but that hasn’t stopped the experienced defender from acting as a mentor to his emerging teammates.
“I try to help them as much as possible,” he added. “I had a good conversation with Ciaran a few weeks ago and I think that helps.
“Of course, we’re fighting for the same position but we need to help each other as well. It’s not about me, it’s not about him, it’s not about Jores – we have to do it together to help the team.”
Now back fit after recovering from a nagging calf problem, Vlaar could be set to return to the line-up for the weekend’s trip to Manchester United, as Okore picked up a knock in training with Denmark last week.