Bernard Jackman has had to deal with a string of player injuries since taking over as Dragons coach this season

Dragons head coach Bernard Jackman is concerned about players becoming addicted to painkillers.

He says a law change is contributing to a rise in injuries among players and fears some are turning to drugs to allow them to play while injured.

"I've heard of a couple of cases of people having issues and addictions to painkillers, prescription drugs and non-prescription drugs," Jackman said.

"That's something that obviously we need to be careful of."

Jackman had the bare minimum of 22 fit players available for last weekend's Pro14 derby at Cardiff Blues, with 29 on the casualty list when he named his side before wingers Jared Rosser and Ashton Hewitt were also forced out after breaking down before kick-off.

The former Ireland, Leinster and Connacht hooker took over at Dragons this season, having had previous coaching experience in France with Grenoble.

As well as the problems of players misusing drugs, Jackman also points to new laws being trialled this season that he believes are contributing to injuries.

Pro14 highlights: Cardiff Blues 43-29 Dragons

"We don't want people to be taking painkillers [to be able to play], we need to make sure our players understand that and also we have the systems and environment in place that they can actually get that recovery," said the 41-year-old.

"There seems to be a crisis at the moment, to be honest.

"It's not just here, it seems something to do with the new law trial around the breakdown that puts more players on their feet - there's less space and the collisions seem bigger."

The laws that have affected the breakdown allow a ruck to be formed by a single player over the ball and on their feet - as opposed to at least one from either team that was previously required - a player can only play the ball from their own side of the tackle, and a defender can no longer kick the ball out of a breakdown.