Turan recently signed a five-year deal with Barcelona reported to be worth €8 million per-season.
The La Liga champions signed just two players this summer but will be unable to play them until January due to the transfer ban imposed on the club by FIFA.
“We need all the players because this season the team has a chance of winning all the competitions we are playing in,” Bartomeu was quoted as saying by the Guardian.
Turan became the first Turkish international to win the La Liga with Atleti and also lifted the Europa League, the European Super Cup, the Spanish Cup and was part of the side that reached the Champions League final in 2014.
The Turkish international has been included in the Barcelona US tour squad but will be unable to play any friendly games as a result of the transfer suspension.
Turan provided six assists and scored three goals in 46 appearances for Atletico Madrid last season.