The Blaugrana continue to be linked with the Dinamo Zagreb and Spain winger, who is keen on a return to the Camp Nou
Olmo has caught the eye in Croatian domestic football and carried his form into the Champions League, with a host of Europe’s top clubs scouting him.
He began his career in Barca’s youth ranks but left La Masia as a 16-year-old for a surprise switch to Zagreb.
There he has blossomed to such an extent he earned a first cap for Spain in November and scored on his debut.
Now Barca are said to be piecing together a deal that would see Olmo join them at the end of this season, with reports Dinamo want over €30 million (£26m/$33m) for the 21-year-old.
Olmo himself has said he is keen on a return to the Camp Nou, saying he is hoping to leave Dinamo “as soon as possible.”
Asked about Olmo on Friday, coach Valverde chose his words carefully but left little doubt he is a player that would be welcomed.
“He is a player that has been here before. He’s a good footballer but he’s with another team and I don’t talk about speculation. We have to be cautious,” he said.
Recent reports have claimed Barca have been knocked back with a first offer for Olmo.
“It’s true that Alena has left,” Valverde said. “I didn’t think it would happen so soon, but he had an option to leave because his contract said so. Now we have one player less in this position and we will see what happens.
“I’m not thinking about more departures, we’ll count on what we have.”
The first test of the new year sees Valverde’s team take on neighbours who brought in a former Barca defender as head coach during the mid-season break.
Abelardo took over from Pablo Machin, becoming Espanyol’s third boss of the season, with a remit to rescue the team from the foot of the table.
The former Barca defender could hardly have asked for a tougher first game, but Valverde said: “When you have a change of coach you always look for a reaction.
“They’re wanting to start the second half of the season with a coach who has experience of these types of situations. I would like them to stay in the Primera.”