Chelsea were reported to have engaged in negotiations with the agent of Jackson Martinez last week, although this has since been denied by Jose Mourinho, and all this speculation appears to have played with the mind of the Porto striker.
The 27-year-old has been supreme in front of goal since joining the club in the summer of last year, scoring 44 times in 58 games, but was profligate on Saturday as Porto's 53-game unbeaten streak came to an end.
Academica triumphed 1-0 on Saturday, their first victory over the Portuguese champions in over 40 years, and Martinez was guilty of spurning a golden opportunity to provide his side with a point from the encounter.
The Chelsea target twice fluffed his lines after the ball was parried out by the Academica goalkeeper, before another player he could move to Stamford Bridge completed a bizarre combined miss at the back post.
Eliaquim Mangala, linked with Chelsea for a number of months, saw his chance to score after Martinez's deflected shot came back out, only to inexplicably fire over the crossbar when the chance appeared easier to convert.