Messi was making his first start of the season after a calf injury but seemed to pick up another problem in the first half of the clash.
He was replaced at half-time by Ousmane Dembele, and Valverde confirmed after the match he was feeling some discomfort.
Reports are already circulating that the injury will keep Messi out of Saturday’s trip to Getafe, where the club will look to pick up their first away win of the season.
Barcelona then take on Inter Milan in the Champions League before welcoming Sevilla to the Camp Nou in La Liga.
Messi will have tests on the injury tomorrow, and the club may offer an indication then of the severity of the problem and if he is indeed set for a spell on the sidelines.
“Wow, adductor injuries can be tricky
A positive might be that Messi gets plenty of rest now so he can be in peak form towards the end of the season. The worry of course is whether we will be in contention to win anything by then” says a Barca fan.