Porto are sweating over the fitness of Jesus Corona ahead of their Euro showdown with Rangers on Thursday.
The winger is a key man for Sergio Conceicao but he's facing an anxious waiting game over the availability of the 40-times capped Mexico international who suffered an ankle injury last month.
The former Twente star was absent from his side's Monday session but reports in Portugal suggest the player is doing conditioning work behind the scenes ahead of the Group G Europa League showdown.
Converted full-back Corona risked the wrath of international boss Tata Martino after flip-flopping on joining his national team during their recent international break.
The former Barcelona boss could barely hide his contempt after the star cried off at the 11th hour before the double-header against Bermuda and Panama in the CONCACAF Nations League.
Martino said: "In the morning, I manifested the idea that even with impossibility (of playing with) the injury he had, we needed him to be with the group to get to know each other, it being the first meeting we'd have had.
"He didn't have to train or play if he couldn't, but we needed him to be here. At first he said yes and then on midday on Sunday, he called to say he'd thought about it and that his ankle wasn't right and that he preferred not to travel.
"He's done something wrong and knows there will be repercussions in the future."
The 26-year-old has made 176 appearances for Porto in all competitions and has scored 24 times for the Primeira Liga big-hitters.
Steven Gerrard's side travel to the Estadio do Dragao knowing a positive result will keep his side's bid to reach the last 32 of the competition on track.
