Sri Lanka lack depth in their fast-bowling battery, coach Graham Ford said, after two frontline quicks left the tour of England with injury, and a third was reported for a suspect action.

Shaminda Eranga is scheduled to undergo a biomechanics test at Loughborough on Monday after he was reported following the Test at Chester-le-Street. Though he is likely to be free to play the Lord's Test - before the results of his test are known - Sri Lanka may opt to save him the extra scrutiny by fielding another bowler in his place.

The selectors will consider handing a debut to 29-year-old left-armer Chaminda Bandara, who is said to swing the ball at a lively pace, but has scarce A team experience. The team's fast bowling stocks have been repeatedly depleted by injury over the past three years. On this tour they have lost Dhammika Prasad and Dushmantha Chameera to injury.

"Maybe it's a little alarming that perhaps we don't have the depth that we were hoping that we would have at this stage, in the fast bowling department," Ford said. "That's a project for the future, because there are those injuries around fast bowlers. I did see some exciting Under-19 bowling before we came out here to England. I'm sure there are talented boys and if they're looked after properly, we should have a decent unit of fast bowlers."

If Eranga does not play at Lord's, Sri Lanka would have effectively lost their best quick of 2015 (Prasad), their fastest bowler (Chameera), and the only quick with over 10 Tests' experience and a bowling average south of 40 (Eranga). It has left a lot on the plate of fast-bowling coach Champaka Ramanayake.

"It is a challenge, because Dhammika was the star of the show last time Sri Lanka toured England," Ford said. "He was the one that bowls the right length and was able to swing the ball both ways. The rest of the guys tend to swing it out more than anything else. And then we lost that extra pace that Dushmantha brings.

"From a firepower point of view we are perhaps not where we want to be. But we do have a bowling unit that can bowl with discipline, hit their areas, and find other ways of creating pressure. Champaka has been working very hard with them on that. We've had periods where we have created that pressure and stuck to it pretty well. But then we've had other periods when we haven't been like that, which shows that we're very much a work-in-progress."

Bandara and Kusal Perera have now joined the squad in London ahead of the third Test, but had their arrival delayed because of visa hurdles. Both men only joined the team in the last 48 hours. Perera had been added to the squad as early as May 22, and as such, had his arrival delayed by about 10 days by the visa process. Ford suggested the delay had been a disadvantage.

"If you're coming to different conditions, the sooner they get used to those conditions the better. The delay wasn't ideal. But now they're here they're going pretty well. Hopefully they have done some good work at home before they got here."

Sri Lanka dropped several key catches across both Tests, with both Moeen Ali and Jonny Bairstow reprieved en route to scores of over 140. The team's catching had been poor in the World T20 and in the previous Test series as well. Ford said systemic changes were required to raise fielding standards in the long term.

"The players have worked like crazy, but at the board level we've talked about how if you want to have a good fielding side, you have to make sure there's real solid coaching in the fielding department at the emerging player level. By the time they get to international cricket they should be good fielders.

"We need somebody at the Under-17, Under-19, development and emerging players having regular fielding sessions. They would have done so many good drills that they're not scared of the ball and not scared to dive. They would watch the ball while they're diving.

"You can't teach an old dog new tricks. You can't flick a switch. You can't have them playing for Sri Lanka and in a couple of fielding sessions turn them into brilliant fielders. We want to be known as a nation that produces really good fielders. In the levels below we've got to get the work done."

Andrew Fidel Fernando is ESPNcricinfo's Sri Lanka correspondent. @andrewffernando