Both Adebola and McKenna joined the Tigers this summer on free transfers from fellow Championship side Forest, and the 33-year-old defensive midfielder could make his debut for the club in their pre-season friendly at North Ferriby on Tuesday.
"Paul McKenna brings a lot of energy and is probably one of the best defensive midfielders in the division," Adebola told the Mail. "He's a natural leader, he was club captain at Forest.
"He had one or two injuries last year but in the previous year he was immense.
"You'd very rarely see him give the ball away and he's got a brilliant pair of lungs. There's a fierce determination in his game to win."