Vincent Aboubakar could replace Martinez in attack

Porto will attempt to continue their unbeaten record in this season's Champions League when they welcome Basel to Portugal for the second leg of their last-16 clash on Tuesday evening.

Julen Lopetegui's side have won six and drawn three of their European games this season and will enter the match as the slight favourites to advance into the quarter-finals after securing a 1-1 draw in the first leg last month.

Porto have also only been beaten once in seven fixtures with Swiss opposition, while they are unbeaten in their last eight European home matches. That said, the Portuguese outfit have lost five of their last six ties at this stage of the competition - reaching the quarter-finals just once since lifting the trophy under Jose Mourinho in 2004.

As it stands, Porto sit second behind Benfica in the Primeira La Liga, but their form as a whole has been strong in recent months - winning seven of their last eight matches and remaining unbeaten in the process.

Basel, meanwhile, have also been in strong form in recent games - winning three of their four fixtures since drawing the first leg, scoring 10 times in the process and conceding just once. They lost 4-2 to Young Boys immediately after the home leg against Porto, but still sit seven points clear at the top of their domestic table.

That said, Basel have never won a competitive match in Portugal - losing on two of their five trips. They have also only won two of the seven UEFA competition ties when they drew the first leg at home. That said, any draw higher than 1-1 would see them advance to the quarter-finals.

Porto will be without the services of star forward Jackson Martinez, who picked up a groin problem in the Portuguese club's 1-0 win over Sporting Braga at the weekend, but the Colombian is their only injury concern.

Ricardo Quaresma is pushing for a spot in the XI, while Vincent Aboubakar could take the place of Martinez in attack.

Basel, meanwhile, could welcome Fabian Schar back into their team after serving a one-game ban, but Marek Suchy is suspended after picking up his third yellow card of the campaign in the first leg. Matias Delgado and Ivan Ivanov will also miss out through injury.