With Alexandre Lacazette recovering from knee surgery and Pierre-Emerick Aubameyang ineligible, England striker Welbeck is expected to lead the line for the Gunners in the two legs of the last-32 tie.
Wenger admits it is hugely frustrating to be without Aubameyang, who cannot play because former club Borussia Dortmund have dropped down into the competition after finishing third in its UEFA Champions League group.
But the Arsenal boss thinks Welbeck looks ready to fill the void in the attack.
Asked about playing the former Manchester United man in a central role, he said: "It's where I prefer him. It's an opportunity for him to do well.
"He had to wait a little to get back into the team, but that gave him time to work on his fitness. He looks sharper than he has in a long time – he looks very sharp."
Wenger feels UEFA should change the regulation that prevents Aubameyang from playing in the competition, especially since Henrikh Mkhitaryan – who joined from United in a swap deal with Alexis Sanchez last month – is eligible to play, despite playing in the Champions League this term.
"Unanimously, I know all clubs agree now that this rule has to disappear," said Wenger. "It doesn't make sense."
Arsenal has taken a strong squad to Sweden for Friday's clash, with Wenger keen not to underestimate a team who progressed from a group containing Athletic Bilbao, Hertha Berlin and Zorya in its group to reach the knockout stages.
The 68-year-old does not expect the cold conditions to prove a problem, though, given the recent inclement weather in England.
"We go to the knockouts; of course the risk is higher," he said. "When I saw them play, I understood why they did well against Bilbao and Berlin. It wasn't a coincidence.
"The temperature, at the moment I don't find too different from London. It shouldn't be a problem."