Fifa have confirmed that teams will be seeded when the soccer governing body makes the draw for the play-off round in the European World Cup qualifiers, avoiding a potential clash between Portugal and Italy.
The winners of the nine European groups go directly to Russia next year while the best eight of the nine runners-up play off over two legs for a further four spots.
The top four teams according to the Fifa rankings would go into one pot for the draw on October 17 while the remaining four will be in another, the world governing body said.
The teams currently in second place in the groups are Sweden (19th in the Fifa rankings), Portugal (6th), Northern Ireland (23rd), Wales (18th), Montenegro (52nd), Slovakia (22nd), Italy (12th), Bosnia (30th) and Iceland (20th).
There are two qualifying matches left to play for each team.
Fifa said the best eight runners-up up would be decided on points, then goal difference, goals scored, goals scored away from home and finally disciplinary ranking.
Matches against the last-placed teams in the groups will not be taken into account.
Wales, in Group D, currently have the worst record of the nine second-placed teams with eight points, not including the two wins against bottom-placed Moldova.