Koeman has decided to use this as a chance to rest his captain, with him having played an important role in Argentina's international fixtures this month.
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Barcelona has been facing injury worries this season and this has reduced their squad depth.
However, Ronald Koeman has decided to leave Messi out of the squad for their UEFA Champions League game against the Ukrainians.
He is being rested as well as is fellow absentee Frenkie de Jong, so he would have to hand call-ups to youth players to strengthen the squad ahead of the tie.
Unlike the La Liga, where Barcelona are struggling to find their form, they have already taken a commanding lead in their group, having won all three games.
Barcelona travel to Ukraine this Monday afternoon with a heavily depleted squad due to their ever-worsening injury crisis, but Ronald Koeman has also decided to leave Lionel Messi out.
On top of Messi and De Jong, Barcelona will have to do without the injured Ansu Fati, Ronald Araujo, Sergio Busquets, Sergi Roberto and Gerard Pique.
The Dutchman has called up young centre-back Oscar Minqueza, who was also selected for the trip to Atletico Madrid, Konrad de la Fuente, and goalkeeper Inaki Pena.
Matheus Fernandes' inclusion also comes as a surprise. Barcelona are travelling to Ukraine on Monday afternoon and are training on Tuesday morning ahead of their match that evening.
Barcelona's squad to face Dynamo Kiev:Goalkeepers: Marc-Andre ter Stegen, Neto, Inaki Pena.Defenders: Sergino Dest, Jordi Alba, Junior Firpo, Oscar Mingueza, Konrad de la Fuente, Clement Lenglet.Midfielders: Carles Alena, Miralem Pjanic, Riqui Puig, Philippe Coutinho, Pedri, Matheus Fernandes.Forwards: Antoine Griezmann, Martin Braithwaite, Ousmane Dembele, Trincao.