James Anderson and Stuart Broad played as England drew the first Test against IndiaStuart Broad will miss England's second Test against India, which starts on Thursday, with James Anderson a doubt.
Broad, 35, has a calf problem, with fears he will not only miss the Lord's Test but further matches after that.
Anderson, 39, has a quad muscle niggle, on which England expect more information later on Wednesday.
Lancashire's Saqib Mahmood has been called up as cover, with Mark Wood and Craig Overton are other pace-bowling options in the squad.
The series is level at 0-0 after the first Test at Trent Bridge was drawn.
England's fast-bowling resources are already depleted. Jofra Archer, with an elbow injury, and Olly Stone, with a back problem, are long-term absentees, while Chris Woakes is out with a heel issue.
All-rounder Ben Stokes has also taken an indefinite break from cricket to focus on his mental wellbeing.
Broad, who has 524 wickets, could have been in line to play his 150th Test at Lord's, but injured his right calf on Tuesday.
Anderson moved to 621 wickets - third on the all-time list - during the first Test. However, he missed training on Wednesday.
Asked if England can cope without their two attack leaders, batsman Jonny Bairstow told BBC Sport: "I don't see any reason why we can't cope.
"We've had a lot of people stand up previously. We don't know exactly what will happen tomorrow, but there might be an opportunity for someone to play a Test at Lord's, and that's an exciting prospect."
Bairstow did admit it is "naturally" a blow to lose bowlers of the calibre of Anderson and Broad, but added: "I don't think it's too much of a destabiliser.
"It's the nature of professional sport. There will be injury and illness at times. You have to be adaptable."
England already looked set to make changes to their side, with spin-bowling all-rounder Moeen Ali likely to come in for a batsman to give greater depth and variety to the attack.
Batsmen Haseeb Hameed and Ollie Pope are also in contention to return.
India will be without fast bowler Shardul Thakur, who has a hamstring injury.
His absence could mean a return for off-spinner Ravichandran Ashwin, who was left out of the first Test despite having 413 Test wickets to his name as India opted for four frontline pace bowlers.
"Four fast bowlers means you can apply pressure in every session," said captain Virat Kohli. "We like playing with that template."
Kohli confirmed that Thakur is likely to be fit for the third Test at Headingley.
