The fly-half is yet to feature so far this term having picked up a back and hip problem during pre-season, but he warmed up with the rest of the squad before their 30-14 victory over Premiership title rivals Wasps this afternoon.
McCall expects the England international to be back available soon, with the possibility of his first appearance of the season coming against Toulon next weekend.
"Owen was with the team for Wasps. He warmed up with them and place kicked for the first time before the game. If everything goes to plan, then hopefully he'll be available for this weekend," he told reporters.
"He's an influential member of the squad and it's good to have him around the team. I think he could definitely come straight into the team, six weeks isn't so long. We'll assess that in training.
"Alex Lozowski has put his case forward so it's a big shout for us, but Owen is a world-class fly-half. For us to have won five of our first six league games without the likes of Owen, Duncan Taylor and Chris Ashton is a good achievement."
The news will also be good for England ahead of the Autumn Internationals at Twickenham.