Celtic were beaten 3-1 by Barcelona on Saturday evening.
Celtic were beaten 3-1 by Barcelona in their second game of the International Champions Cup, but two players appear to have caught the eye of supporters.
The Bhoys, who drew 1-1 with Leicester City in Glasgow last weekend to kick off their tournament, headed to Ireland on Saturday to take on the La Liga champions - and were swept aside by Lionel Messi and co.
Arda Turan put Barcelona in front before Leigh Griffiths grabbed an equaliser for Celtic, but an Efe Ambrose own goal and a close-range strike from Munir El Haddadi gave Luis Enrique's men the win at the Aviva Stadium in Ireland.
Celtic are now back in Champions League action on Wednesday, as they face Astana in the second leg of their qualifying clash, and manager Brendan Rodgers has some selection decisions to make.
Celtic manager Brendan Rodgers
Rodgers gave a number of players a chance against Barcelona, and fans appear to have been impressed with two of his half-time substitutes.
Midfielder Kristoffer Ajer was Ronny Deila's final signing as Celtic manager, but has been playing in the heart of defence under Rodgers, showing some promise in his new position.
Fans tipped him to start at centre back alongside Eoghan O'Connell for the second leg against Astana, praising him for his excellent defending against Barcelona as supporters want to see him start instead of Efe Ambrose.
Celtic's Nadir Ciftci in action
Another substitute who impressed was forward Nadir Ciftci, who took up a position on the left wing despite normally being a striker. The Turkish forward endured a difficult first season at Celtic last term, and even spent the second half of the campaign on loan with Eskisehirspor before returning to fight for his Bhoys future under Rodgers.
Supporters took to Twitter to praise Ciftci, claiming he looks like a new player and should be given a chance to shine this season based on his pre-season performances.
Ciftci looks like a new player, was happy when we signed him but never showed the potential hopefully does this season— Eliot Ardrey (@JoppyGabberheid) July 30, 2016
Nadir Ciftci has surprised me, his work rate and all round play has improved. Think he needs to stick around to see if he evolves further— John Thomas (JT) (@HealthFitnesIre) July 30, 2016
Really impressed with ciftci during pre season. Playing like he's out to prove something— Anthony Conroy (@anthonyconroy14) July 30, 2016
Ciftci looks a new player. Hope hes given a chance this season— Hun_Skelper (@bhoy_belfast) July 30, 2016
Ajer, Allan, Rogic, O'Connell, Brown, Ciftci all looked good tonight— Marc (@marc_celtic) July 30, 2016
Looking at Ajer in pre-season, I'd honestly rather he, as a teenage attacking midfielder, played CB for us ahead of a 50+ caps CB in Efe.— TheGlassCutter (@TheGlassCutter) July 30, 2016
Ajer and aconnell could be the pairing midweek! Both young but read the game well....— B.Elder (@YNWACFC1) July 30, 2016
What did you think of Ajer and Ciftci's performances against Barcelona?