The Manchester United forward is being assessed by medical staff after a training session at England's World Cup headquarters in Urca.
Welbeck is understood to have trained with strapping around his thigh before limping out of the session early.
England are expected to give an update on Welbeck's fitness on Wednesday, with the clash against Italy in Manaus just three days away.
Injury to Welbeck would leave England with a selection issue after Roy Hodgson indicated Alex Oxlade-Chamberlain is only expected to be fit to face Uruguay on June 19.
"Alex Oxlade-Chamberlain did well yesterday and we will be stepping up his training programme during the course of the week," Hodgson told reporters.
"The medics are hopeful he will be fit by the second game [against Uruguay]."
Hodgson has, however, played down suggestions Steven Gerrard is struggling with a tight groin and has no injury concerns over the England captain.