Chelsea will try to remain unbeaten at the Union of European Football Associations (UEFA) Champions League when they visit FC Porto (FCP) at Estádio do Dragão today. 

The Blues are currently on top of Group G in the Champions League after a dominating 4-0 victory over Maccabi Tel-Aviv in their season opener. 

Following the win against Maccabi Tel-Aviv, the Blues have not lost in their next three matches but had a 2–2 draw in their last outing, which was in the Premier League against Newcastle United. 

The good news for Chelsea is they will have striker Diego Costa against Porto since the Brazilian's three-game ban does not take effect in European games, according to BBC Sport. 

Costa received the suspension after being charged by The Football Association with violent conduct because of his involvement in physical and verbal altercations in their win over Arsenal. 

Meanwhile, Porto is unbeaten this season in seven matches played in all competitions having four wins and three draws, with their most recent a 2–2 draw at the Primeira Liga facing Moreirense. 

In the Champions League, FCP has one point tied with Dynamo Kyiv, whom they faced in their opener that ended in a 2–2 draw. 

Porto manager Julen Lopetegui had this to say against Chelsea, according to BBC Sport, "They have kicked off by winning 4–0 and that says how they are going to hang on to this competition, which is the most important at a club level."

"That they started their own league better or worse has no impact. They are great team with great potential at every level," Lopetegui added. 

The matchup of Chelsea and FCP will feature the meeting of Blues manager Jose Mourinho and Porto goalkeeper Iker Casillas. 

Before Casillas transferred to Porto, he was with Real Madrid, which was then managed by Mourinho. 

The relationship of the two reportedly went downhill after Mourinho benched Casillas in his last few years in Real. 

The Champions League match between Chelsea and Porto will be today, Sept. 29, at 2:45 p.m. EST. To watch via live stream, click here.