The defender has been linked with a move away from the Championship club this summer.
The Republic of Ireland international has been linked with a move to West Bromwich Albion during this window, the Express and Star reports. But with no offers being put on the table, Di Matteo has explained why he is confident that the 26-year-old will be going nowhere in the near future.
Roberto Di Matteo
"Ciaran is a Villa man, a Villa boy, he has pledged his future to us, he will be staying with us," he told the Express and Star.
"He is very happy to be with us, to stay here. I know he has a long-term contract as well."
Despite Di Matteo's confidence, the decision about Clark's future may well be out of his hands. The Express and Star reports that the centre-back has a release clause of just £5m, so if the Baggies, or any other interested club decides to make such a bid, there will be little he can do to prevent a move going through.
However, if he has not done so already, he may attempt to convince Clark that he is trying to create something special that will not only see the Villains get back into the Premier League, but will also see them surpass the doldrums they were in for several years before their relegation.
And if he is able to convince Clark that he wants him to be a crucial part of that project, then it may make it very difficult for another club to prise him away, even if they trigger his release clause.