Junaid Khan pitched the ball on what was a perfect length for a bouncer, but Kithuruwan Vithanage dismissed him to the midwicket boundary with a powerful pull. The bouncer used to be a standout feature of Junaid's bowling - jagging back at the batsman's throat from outside off - but something is now missing, and it has been so since the tour of Bangladesh earlier this year.

On the fifth day of the Test at the P Sara Oval in Colombo, Junaid was removed from the attack after his second over. He finished with figures of 0 for 30 in four overs to go with his 29-5-89-1 in the first innings. He had gone wicketless in Galle, and is now a doubtful starter for the third Test in Pallekele, with Pakistan captain Misbah-ul-Haq saying Junaid's form was a "worrying sign" for the team.

"I really don't know what is happening with him but I think maybe after injury he is not able to gain the confidence and rhythm that is required," Misbah said of Junaid after Pakistan lost the second Test by seven wickets. "We expected that after playing a couple of matches he might find his form, but I think it's a worrying sign for us. Lets see how it goes. We have other options in the form of three more seamers and we will take a call after looking at the conditions there."

Junaid burst on to the international circuit soon after the spot-fixing scandal in 2010 and his success gave Pakistan a reason to look beyond the banned Mohammad Amir and Mohammad Asif. He took a five-wicket haul in only his second Test and developed into Pakistan's first-choice fast bowler despite most of the pitches he played on being placid UAE surfaces. After 14 Tests, he had 50 wickets to Amir's 51 in the same number of matches; Junaid's cost 27.54 apiece while Amir took his at 29.

Between 2011 and 2014, he was Pakistan's best bet after Saeed Ajmal and Misbah once said they were the kind of bowlers who made life easy for him. Shorn of home games because of security reasons, Junaid's services helped Pakistan rebuild after the troubles of 2010. It was a delight to watch him bowl, his orthodox run-up beginning with a little jump that gives him the rhythm to steam in.

Four years later, Junaid is arguably the weakest link in Pakistan's attack on this tour of Sri Lanka. His pace and movement are diminished, his lengths inconsistent, and his demeanour unthreatening. And before this tour, he had enjoyed tremendous success against Sri Lanka - 49 of his 70 wickets were against them at 26 apiece. It's hard not to feel for him.

Junaid's problems began in October 2014, when a grade 3 osteochondral fracture in his knee forced him to miss series' against Australia and New Zealand in the UAE. He recovered to be named in the squad for the one-dayers in New Zealand ahead of the World Cup, but had a fall while training at the National Cricket Academy in Lahore. He missed those ODIs and was subsequently ruled out of the World Cup too. Since his return, Junaid has six wickets in four Tests, the leanest patch of his career.

It could be argued that Junaid could have been eased back into international cricket after some practice games at home. He was bowling in the nets during his rehab at the NCA and he did not play any competitive cricket before being sent on the tour of Bangladesh after the World Cup, having been out of action for almost eight months.

Now, with Rahat Ali coming in for the injured Wahab Riaz, and Ehsan Adil and Imran Khan on the bench, Junaid might not make the cut for Pallekele. "He might be dropped and why not?" said Ramiz Raja, the former Pakistan captain. "He is one fine bowler but after injury it's quite natural. He might have lost his pace, which happens after injury, but he can revive himself and regain his confidence with time."

Umar Farooq is ESPNcricinfo's Pakistan correspondent. @kalson