Chelsea's pursuit of Jackson Martinez relies on Porto's elimination from the Champions League, according to John Cross of Mirror Football.

Speculation has increased about the Londoners' interest in Martinez, with Cross highlighting secret talks held by Roman Abramovich's trusted lieutenant, Marina Granovskaia.

However, regardless of the nature of these conversations, it seems a move depends entirely on Porto's Champions League fate.

Should they progress to the round of 16, it seems the Portuguese club have every intention of clinging on to their prized possession for the knockout stages.

What will encourage Chelsea fans is how Porto's hopes appear as good as over.

A frustrating 1-1 draw at home to Austria Vienna looks like condemning Paulo Fonseca's side to the Europa League, following a disappointing campaign.

Martinez scored his side's goal against Vienna but will be disappointed with his overall production. He was erratic in front of goal and hit nine shots, according to WhoScored, spurning numerous openings including a key chance at the end.

A point behind Zenit St. Petersburg—who travel to Austria for their final clash—Porto must beat an undefeated, already-qualified Atletico Madrid, while hoping the Russians fail to claim maximum points.

Otherwise, all options point to the Europa League, potentially without their top scorer.

Despite his troubles against Vienna, Martinez has still managed eight goals in just 10 league games this season and seems ready to make a major career move.

His overall record at Porto is impressive. He finished as top scorer last season with 26 goals, per WhoScored, and having just turned 27 is very much in his prime.

Cross also refers to Chelsea's ongoing interest in Falcao, claiming Martinez—while heavily sought after—remains second choice behind his Colombian compatriot.

Either would be an extravagant but necessary buy for Abramovich, with Chelsea's lack of firepower transparent to all.

Samuel Eto'o's injury sustained against Basel only heightens the need for new additions in order to launch a prolonged title charge.

Man-for-man, Manchester City's forward options are a cut above their rivals, and if Chelsea hope to mount a better push for the Premier League crown, forward reinforcements are a must in January.