Sri Lanka's preparations for the first Test in Cardiff have taken a blow with the news that Nuwan Pradeep, their match-winning seamer against the England Lions on Sunday, is set to fly home after picking up a knee injury.

Pradeep claimed figures of 4 for 29 in ten hostile overs as Sri Lanka overcame the follow-on to bowl the Lions out for 183 in Derby and win a thrilling contest by 38 runs. However, he sustained damage to his anterior cruciate ligament after treading on the ball in the course of that spell, and is expected to be out of action for six to eight weeks.

"It's bad news for the young man," said Stuart Law, Sri Lanka's interim coach. "The warmer you are the better with these injuries, but as he stopped he was dragging his leg around yesterday. It's a shame."

In the absence of their limited-overs spearhead, Lasith Malinga, Pradeep had looked likely to slot straight into the Test team with his extra pace through the air and unorthodox slingy action. "He was definitely in the mix after his performance in Derby," said Law. "He's one of our cards up our sleeve, so it's a shame if he has to go home. I'm heart-broken for him."

Sri Lanka's problems could be compounded by the potential loss of their veteran seamer Dilhara Fernando, who was limping during training after bowling through the pain of a less serious knee problem during that same match in Derby, in which he took six wickets. He was named in their 12-man squad for Thursday, but remains in doubt.

Farveez Maharoof, who has been playing county cricket for Lancashire, has been drafted into the squad as cover, having already featured during their opening warm-up match against Middlesex in Uxbridge, when several members of the original 16-man squad were still in India playing the IPL.

Given his form for Lancashire and his all-round abilities, Maharoof could well end up playing his first Test since 2007. He started the season with a century on Lancashire debut and followed the tour game against Middlesex, in which he took two wickets, with a four-wicket first-innings haul for Lancashire against Yorkshire.

Sri Lanka's other seam-bowling options are Suranga Lakmal, Thisara Perera and Chanaka Welegedara. Perera took four wickets at Derby, while Lakmal and Welegedara took three and five wickets respectively in the game against Middlesex.

Maharoof played 20 Tests between 2004 and 2007, and was a regular in Sri Lanka's one-day side till early 2009 after which a combination of injuries and the emergence of Angelo Mathews as Sri Lanka's premier allrounder kept him out of the national team. He made a comeback during the 2010 Asia Cup but has not played any international cricket since.

"We've drafted Maharoof in as injury cover, and it's the perfect opportunity to get him involved because he's been here a long time," said Law. "He's been playing well for Lancashire, we've got good reports from the Lanky boys saying he's fitted in well - bowling well, batting well, he's a good man around the dressing room - so it was natural, rather than have someone who's been sitting at home doing nothing. It was a common-sense decision."

Maharoof's inclusion in the Sri Lanka squad means he is unlikely to be available for Lancashire until the end of the tour in mid-July.