Barcelona had Sergi Roberto sent off while 2-1 ahead, and were ultimately made to settle for a point in Vigo.
The Catalan giants, who stretched their unbeaten league run to 40 matches, are now 12 points clear of second-placed Atletico Madrid in La Liga.
"I wasn't happy with the draw because we always want to win, but we'll settle for it. We were in control of the game at 2-1 up, but then the red card and they threw themselves at us," Valverde told reporters.
"Ultimately we had to suffer, but it's one more point for us and we're only two wins away from becoming champions."
Next up for Barcelona is the final of the Copa del Rey against Sevilla on Saturday night.