The Hearts manager believes combining the talents of the Scot and the Ugandan can help secure a top-six place, after which Hearts will begin pursuing a place in Europe.
Recent matches against Hibs and Rangers saw Glen and Obua paired together up front and offered encouragement to a team criticised for lacking goals.
Obua's aerial presence and Glen's predatory instincts looked compatible and Jefferies will keep faith with both players for the foreseeable future.
And he says it may even be next season before the partnership flourishes properly.
"I was very pleased with Gary Glen in the first half last week," said Jefferies. "He put a lot of effort into the game and tired a bit in the second half but I am really pleased with his partnership with David Obua.
"They are just new together and it's a new position for David but I think it's only going to get better and better. It might blossom next season after we have had a chance to work with them during the pre-season. It's not going to happen overnight, you have got to keep working on things in training but it is very encouraging."
Glen and Obua were expected to start this afternoon's game against St Mirren in Paisley, with Hearts due to conclude their pre-split fixtures with a home match against Kilmarnock next Saturday.