Porto are sweating on the fitness on Cameroon star Vincent Aboubakar for their upcoming first-leg of their Champions League knockout stage against Liverpool first-leg of their Champions League knockout stage.
The 26-year-old forward didn't practice with the rest of the squad on Tuesday because of a lingering muscle injury and remains doubtful for the match at Estadio do Dragao.
Abubakar hasn't played in the last two matches for the Primeira Liga league leaders and missing the derby against Sporting Lisbon in the Portuguese Cup and the league match at Chaves.
Abubakar has been in red-hot form for Porto this scoring 20 goals from 28 matches, including five of the team's 15 goals in the group stage of the Champions League.
The Primeira Liga is unbeaten in its last 23 matches in all competitions and only lost once at home - 3-1 against Besiktas in the group stage saw them finishing second behind the Turkish giants of the European premier league tournament.
Porto has never beaten five-time European Champions Liverpool in their four meeting drawing two and losing two with Reds are hoping to reach their first Champions League quarter-final since 2008-09.