The Swede had to be substituted midway through the second half of PSG's 3-1 quarter-final first-leg victory at the Parc des Princes after appearing to
hurt his right thigh while playing a pass to Christophe Jallet in midfield.
"It's a muscular problem. He will see the doctor ()," confirmed Blanc, who immediately decided to replace the striker with Brazilian winger Lucas.
"He wanted to continue but I thought honestly that it wasn't reasonable. I hope he comes back as soon as possible because we need him."
Ibrahimovic, who has scored a club record-breaking 40 goals in all competitions this season, including 10 in the Champions League, faces a race against time to be fit for the second leg at Stamford Bridge .