The Belgium worldwide has been moved centrally by Antonio Conte at times this season, with the Blues prepared to function without an out-and-out striker.
Willian's superb goal, after two wondrous shots off the post in the first half, had squeezed Chelsea a lead after a period of threatening play.
Valverde said Barcelona managed to get an error out of Chelsea's defence which paved way for Lionel Messi to score his first goal against the Blues. Marcos Alonso drew a routine save out of Marc-Andre ter Stegen with a free-kick from 25 yards out on 31 minutes, before Willian smacked an effort against the right post from 21 yards out two minutes later.
"Sometimes it was like a game of handball because they dropped back and waited, but we didn't lose patience and our performance was very complete".
"I think in the second leg, we have to play our game against Barcelona".
US women back in gold medal game after win over Finland
This was the USA women's first gold since 1998. "I've never imagined our team connecting this well". Even so, getting to Pyeongchang at all was not a foregone conclusion for this team.
Before this tie, Chelsea coach Antonio Conte claimed his side would need a "perfect game" if they were to progress, and Christensen will be all too aware that his mistake was the difference. "Against this opponent, this type of player like Messi, Iniesta, [Luis] Suarez ... if you make a mistake, you pay", Antonio Conte said after the match.
The Argentine levelled for Barcelona 15 minutes from time at Stamford Bridge, after a wayward pass from Andreas Christensen was pounced on by Andres Iniesta.
"We go home today thinking that we completed good work, competed very well - we should be proud of that - but at the same we are also sad".
The away goal gives Barcelona the crucial advantage ahead of Leg 2 at Camp Nou on March 14. "We hope to get better luck in Barcelona". I am very happy.
"At times it seemed like a handball match, because they sat back and waited", said the midfielder. "We have to win, we have to score".