Defeat for hosts Gabon will eliminate them from the Africa Cup of Nations but a win in their crunch game against Group A leaders Cameroon in Libreville will be enough to take them through to the quarter-finals.

An early exit for the hosts threatens to put a dampener on a tournament which is already struggling to attract fans to the stadiums.

There have been empty seats at the Stade de l'Amitie, with its capacity of almost 40,000, in each of Gabon's games thus far.

And there are some fears that an early exit for the hosts could lead to unrest in Gabon.

This is in addition to existing concerns the tournament could be disrupted by large political protests against President Ali Bongo, who was re-elected last year in a close and tense election.

Bongo paid a visit to the team on Saturday, with about 50 soldiers with automatic rifles surrounding the training field, and he left them in no doubt about what is required of them.

Goalkeeper Didier Ovono said: "The message was clear. The expectations are very high. We have no other choice but to win that match.''

Gabon have drawn both their games so far, with two goals by star man Pierre-Emerick Aubameyang.

Another draw might be enough for Gabon to qualify but they would need the other Group A match between Burkina Faso and Guinea Bissau, which will be played at the same time in Franceville, also to end in stalemate but with fewer goals.

Gabon go into the game weakened by the losses of both Juventus midfielder Mario Lemina and full-back Johann Obiang to injuries.

Cameroon coach Hugo Broos has revealed that Christian Bassogog is "suffering a little bit with his ankle" which has affected his ability to train. However, the forward is expected to be fit.

The Indomitable Lions need only to avoid defeat to qualify and Broos said: "We know what we have to do. We have to concentrate on our ourselves not on Gabon, look at our own game and way to play.

"The pressure will be enormous on Gabon's shoulders. The most important thing is for us to be in the game from the first second - if we go on the pitch with that mentality it will be even more difficult for Gabon."