Four teams are competing for second place in European World Cup qualifying Group B but face missing out on a spot in next month's play-offs.
Bulgaria are best placed to finish second, behind group winners Italy, but currently have the lowest points total of all the nine second-placed teams in the European section and are therefore on course to miss out on the play-offs, which will be composed of four two-legged ties.
Denmark, the Czech Republic and Armenia can all still finish the group in second place. Denmark are behind Bulgaria only on goal difference, while the other two are a point behind.
Bulgaria host the Czechs while Denmark take on bottom side Malta and Italy welcome Armenia to Naples.
"With the exception of Malta, they all have the possibility to finish second in the group," Italy coach Cesare Prandelli said to Gazzetta dello Sport. "It's going to be an interesting finish."
Bulgaria's play-off chances suffered a hit in a 2-1 defeat away to Armenia on Friday, their second loss in qualifying.
Bulgaria coach Luboslav Penev will be without defender Nikolay Bodurov and midfielder Svetoslav Dyakov, with both suspended after being sent off against Armenia.
The Czechs, by contrast, go into the encounter in Sofia on the back of a 4-1 triumph in Malta - their biggest win in qualifying.
Denmark are still coming to terms with Friday's 2-2 home draw against Italy.
The Danes were close to achieving a win which would have seen them leapfrog Bulgaria into second but conceded a late equaliser.
"It was quite a blow," Denmark midfielder William Kvist said.
"We came so close and it really hurts."
Denmark, coached by Morten Olsen, face Malta in Copenhagen looking for their first home win in qualifying.
Malta lie at the foot of the standings with just three points taken from a possible 27.
Italy host in-form Armenia looking to end their qualifying campaign in style.
The Azzurri have won six of their nine group games but came close to seeing their unbeaten run end last Friday.
Prandelli hopes to have AC Milan striker Mario Balotelli back, after he missed the game against Denmark with the flu.
Armenia travel to the Stadio San Paolo having won three of their last four qualifiers.