But Messi's return at the Johan Cruyff Stadium was perhaps the biggest plus for Koeman, who was taking charge of his first game since being appointed coach last month.
His comments came after his side earned an underwhelming 3-1 win over Gimnastic de Tarragona in a pre-season friendly on Saturday.
Barca are sitting out the first two weekends of the new La Liga season which began on Saturday due to participating in the Champions League "Final Eight" tournament last month.
"For us, it's now very important to have Leo in the best conditions to play".
United States youth global Konrad de la Fuente has also been included, and Philippe Coutinho could also be involved after returning from his loan spell with Bayern Munich.
So desperate is Koeman to get rid of the striker, Barça would be willing to let him leave for next to nothing, but a permanent transfer going through relies on Suarez agreeing to lower wages at a different club.
Lionel Messi made his return for Barcelona for the first time since his dramatic transfer U-turn by playing 45 minutes.