Iniesta sustained a hamstring injury against Atletico Madrid on March 4 but the midfielder took part in a light training session on Monday ahead of the last-16 second leg at the Camp Nou. The first leg finished 1-1.
“It’s clear when a match like this arrives, a player tends to risk,” Valverde said on Tuesday.
“What we have to decide is whether the risk is excessive.
“He played a big part of the training session yesterday without a problem. We’ll see how he feels today and decide.
“It’s a very important game. It’s down to the player. It’s a game you can only play if you’re 100 per cent.”
Iniesta could be replaced by Paulinho in the starting line-up but the Spaniard’s absence would represent a major blow to his team’s hopes of reaching the quarter-finals.
“We know what Andres brings to the team, not only on the pitch but as a captain,” Barcelona midfielder Sergio Busquets said.
“You give him the ball and he always knows what he has to do to create chances. Everything that he contributes is postive. He is training and we hope he plays.”
Lionel Messi, however, is available again, after the Argentinian missed Saturday’s win at Malaga to attend the birth of his son, Ciro.
“He will be fine,” Busquets said. “In fact he will be more motivated than what we are used to and physically he is going to be great, after having an extra game’s rest. I hope that this is perfect.”
The 33-year-old Spain midfielder has been linked with a summer move to the Chinese Super League (CSL), which has attracted a number of big-name foreign players.
Veteran defender Javier Mascherano left Barcelona in January for Hebei China Fortune, joining the likes of the Brazilians Hulk and Oscar in the CSL.
But Tianjin moved to quash the rumours about Iniesta, issuing a statement saying: “Our club solemnly state that such news reports are false. For all false reports about our club, we reserve the right to solve it through legal means,” the statement said.
Barcelona daily Sport said last month that Iniesta, who will be 34 in May, had been offered 35 million euros a season to switch to Tianjin.
Iniesta, scorer of the winning goal for Spain in the 2010 World Cup final, signed a “lifetime contract” with Barca last October.
Ambitious Tianjin already have Brazilian forward Pato and Belgian international midfielder Axel Witsel on their books.
They were previously linked with striker Diego Costa, who is now at Atletico Madrid after leaving Chelsea.
The veteran trained for a part of Barca’s routine session as he continued his recovery from a hamstring injury that he sustained against Atletico Madrid last Sunday.
Speaking on Iniesta’s absence, Ernesto Valverde had said: “Without Iniesta we lose a unique player, irreplaceable. It’s difficult to find a substitute for his because there is no-one like him in the world. Let’s hope the injury is nothing serious.”
Meanwhile, Catalan Radio said Iniesta will be fit to start the Champions League game against Chelsea on Wednesday.
— FC Barcelona (@FCBarcelona) March 12, 2018