The former Leeds United winger only became a Tigers player on the morning of Thursday's Championship clash with Boro, signing permanently from Barnsley following his spell on loan at the KCOM Stadium.
Wilks' temporary deal in East Yorkshire formally expired earlier this week and although City had the option to make his January switch a permanent one, the deadline to conclude that move also passed on Tuesday.
An agreement was eventually struck between the two Yorkshire clubs, though the player himself was left in a state of limbo, unsure if he would have to remain at Oakwell, where he has been frozen out by Gerhard Struber.
Yet, despite the uncertainty surrounding his situation, Wilks still came up with the goods out on the pitch, firing home from Jordy De Wijs' knock-down to hand Hull a first win in 14 league matches and lift them out of the drop zone.
"I'm really, really pleased with Mallik," McCann said following his team's 2-1 victory.
"That's almost the bonus goal, in the right place at the right time.
"I'm delighted for him because he's had a bit of a tough time over at Barnsley and even over the last few days it's been really tough for him with things that have gone on - but he's produced right at the end.
"He didn't know whether he was coming or going the last couple of days.
"There were a lot of complications in and around trying to get the deal done but we're really pleased [to get the deal done]. It's been really beneficial for us and he'll be a big player for us in the next couple of years."
While a first league triumph since New Year's Day boosts Hull's chances of survival, it also dents Barnsley's.
Asked if he was surprised that the Tykes let match-winner Wilks join a relegation rival having previously refused to extend his loan deal, McCann replied: "They had no choice.
"The deal was done in January, it was all agreed, but there were complications around things regarding other issues, but they had no choice.
"We had an option to buy. Mallik's contract and everything else was done in January."