Last week's goalless draw was the first time either side failed to score in the competition this season and both would have worked on their finishing in the buildup to Tuesday's return encounter.
Al Taawoun would have been the happier with the first leg result, with the Saudi Arabia side having to cope with incessant pressure for most of its match.
Its defensive resilience meant walking away without conceding and Al Taawoun will count on its fans to push them through at the Wolves Park.
Iran's Tractor would have been disappointed with the first leg result, peppering Al Taawoun's goalmouth with 16 shots - six of which were on target.
Tractor, however, will be optimistic of its chances as Al Taawoun is beatable at home - as shown by Iraq's Air Force SC who beat the team 2-1 in the group stage.
The match will be held at the Al Taawoun Club Stadium in Buraidah.