THE AFL Players' Association has expressed concern that Western Bulldogs' midfielder Clay Smith was sent back on the field on Saturday after injuring his knee.

However it is prepared to accept the explanation from the club for the decision.

The 22-year-old suffered an ACL injury midway through the second quarter but was sent back on to the ground only for his knee to buckle moments before the half-time break.

The Bulldogs explained in a media statement on Monday morning the process that took place after the initial injury.

The club also presented a briefing on Monday to the AFL's football operations department to explain what had occurred.

An AFL spokesperson said the League was satisfied the Bulldogs had an informed discussion with Smith, as they are required to do and accepted their actions as appropriate in the circumstances.

On Monday the Association also spoke with Smith, his manager Marty Pask, the Bulldogs and the AFL about the circumstances of his injury and the process that followed after he was injured. AFL.com.au contacted Pask who declined to comment.

The Association's player relations' manager Ian Prendergast said questions were asked because they were concerned a club would send a player on to the field who had suffered a serious injury.

"AFL club doctors perform a very difficult task and are required to make decisions on serious matters in high pressure situations and under tight time constraints," Prendergast said.

"While we do not wish to second guess the decision-making of the medical team in this instance, it is concerning that a club would send a player back on to the field who has already suffered a serious injury."

Smith had already had two knee reconstructions before damaging his knee on Saturday.

AFL Medical Officers Association executive Dr Hugh Seward told AFL.com.au the club's decision was understandable.

"Sometimes extremely unusual medical circumstances can lead to medical decisions that might seem unusual but are in fact appropriate," Seward said.

He said the fact Smith had already suffered two ACL injuries made it a unique case.

Dr Peter Larkins also backed the club's decision and explanation.

The Bulldogs said their inquiries and the advice of independent experts led them to conclude that the medical judgments made by the club's doctors were appropriate.

The AFLPA has vowed to monitor such cases as they occur.

"The AFL Players' Association will continue to work with the AFL, the clubs and medical officers to ensure that best practice procedures are followed in all cases," Prendergast said.