Luis Suarez, meanwhile, sat in the stands after being left out of the squad again by Koeman, although he could be set to stay after Juventus coach Andrea Pirlo said earlier in the day that the Uruguayan was unlikely to join the Italian champions.
Barca took most of the initiative but could not build on their lead against Elche, who have been promoted back to La Liga after a five-year absence and stayed in the game until the end.
Diego Bri should have equalised for the visitors late on but was thwarted by an impressive save from Barca keeper Neto.
Portuguese winger Francisco Trincao continued to impress in his third appearance and should have doubled Barca's lead after combining with Philippe Coutinho, but he was denied by a good save from Elche keeper Edgar Badia.
Koeman fielded a close to full-strength side but surprisingly left home-grown midfielder Riqui Puig out of the squad, with Catalan media reports saying the coach has told the youngster he is not in his plans for the coming campaign.
The Gamper is traditionally a festive occasion against some of the biggest sides from around the world, with Arsenal and Boca Juniors visiting in the last two years.
But this was a far more subdued occasion, played at an empty Camp Nou due to continued coronavirus restrictions and against a rather less glamorous outfit in Elche.
Barca begin their La Liga campaign next Sunday at home to Villarreal.