Ten Hag pleased United showed will to win against Omonia
United had 34 shots and dominated possession in the Group E encounter but were unable to break the deadlock until substitute McTominay scored in the 93rd minute.
"I would say the performance till the box was good, but then the finishing of course was not that good. Let's hope that we have saved the goals for the coming week," Ten Hag told reporters.
He said his team have enough creativity to win matches but that some of his players just had an off-night in front of goal.
"What the good thing is, and I have to credit the team for that, they keep going and they don't give up," he added. "They keep believing (that they could) score and in the end, they got rewarded. And that is the way you have to do it."
Group leaders Real Sociedad have sealed their spot in the next round while United are six points ahead of Sheriff Tiraspol, with Omonia bottom after losing all four of their games.
United host Sheriff on October 27th before finishing their Europa League group campaign with a trip to Spain to face Real Sociedad on November 3rd.