Porto boss Sergio Conceicao insists his players have nothing to prove in Tuesday night's home Champions League tie against Manchester City.

Conceicao's side will seal a place in the knockout stages alongside City with victory at Estadio do Dragao in their penultimate Group C match.

Porto have taken maximum points from their three group games since losing 3-1 to City on matchday one, against Olympiacos and then Marseille home and away, and they have won their last four games in all competitions.

"It is not the ideal game to prove anything, it is to be faithful to what we worked on," Conceicao told a press conference. "We don't have to prove anything to anyone."

Conceicao was critical of City boss Pep Guardiola's touchline behaviour after the two sides clashed at the Etihad Stadium.

The Portuguese's claims that Guardiola and his backroom staff attempted to influence officials during that game is sure to add spice to Tuesday's encounter.

Conceicao has urged his players to maintain their focus after Saturday's 1-0 league win against Santa Clara left them fourth in their domestic table, four points behind leaders Sporting Lisbon.

"We have to get into the game freed from everything," he said. "With an ambition to win and the characteristics that are part of our team. In these games everyone is motivated.

"Offensively we are a team that creates a lot. Now it also depends on the value of the opponent."

Porto head into the game three points behind City and six ahead of third-placed Olympiacos, who play Marseille in France on Tuesday night.