"Obviously, his goals would be a massive loss but I don't know if he's going or if he's not going," said Jagielka via the Express.
"It would be up to the manager and the club to replace him.
"If we sign two players in his place and they both score 15 goals, then OK.
"Most clubs would want Romelu Lukaku in their team.
"If it's not to be us next season, we have to make sure we've got people that either come in or step up to the plate.