Walcott was eventually replaced with six minutes left after suffering the problem during the first half.
Manager Arsene Wenger revealed the forward would need to be assessed ahead of next Wednesday's friendly match in Stockholm.
"Walcott has a glute muscle problem," said Wenger.
"We nearly took him off at half-time, he nearly went down, but we left him on and on.
"In the end, it got worse and worse. At the moment, he is limping so I do not know whether he will be able to join the national team or not."