James Anderson on Sunday suffered a knee injury after being hit on the inside of his leg during Lancashire's four-wicket defeat by champions Hampshire in a One-Day Cup semi-final.
The 36-year-old Anderson left the field mid-over after being struck by a drive from James Fuller and will now require further medical assessment on Monday.
"It is a nasty blow in a painful area," said Chapple. "We don't know but we think that it will be a nasty bruise that will settle down in the next few days.
"The physio will see him in the morning and he walked off there."
Chapple, himself a former Lancashire paceman, added: "It is a difficult area. As soon as there is any swelling in there it will restrict your movement and limit your strength. I imagine it will be painful for a few days."
Anderson's tally of 575 Test wickets is the most by any fast bowler in history, with only the spin trio of Muttiah Muralitharan (800), Shane Warne (708) and Anil Kumble (619) ahead of him.
As Anderson no longer plays limited overs cricket, this injury will have no bearing on tournament hosts England's squad for the upcoming World Cup.
And there ought to be plenty of time for Anderson to recover before England's bid to regain the Ashes starts with the first Test against Australia at Edgbaston on August 1.