The criticism came during the sentencing of a former Ashley youth worker over the assault of an inmate at the Deloraine facility last year.

Launceston's Lincoln John Goodyer, 39, was sentenced to an 18-month good behaviour bond on Thursday for throwing a basketball in the face of an inmate.

There were no lasting injuries to the victim.

Goodyer assaulted the 17-year-old after the youth verbally abused him.

Defence counsel Adrian Hall told the court that Ashley was a stressful place to work and staff were often abused verbally and physically.

He said Goodyer, who had no prior convictions, had snapped when dealing with the ``really foreign matter'' that was only his second day shift during seven years as a youth worker there.

Initially a Chubb security guard at Ashley, Goodyer transferred to a youth worker position after the centre began phasing out external security contracts.

He told Magistrate Reg Marron it was common for youth workers to take up the duties of security guards if necessary.

``So basically what you are saying is they are (permitted) to interchange security workers with youth workers out there?'' Mr Marron said.

``(That) dilutes the whole purpose of having a youth facility.''

He then asked Goodyer if he had ever discussed with his employer how to deal with feeling ``at risk of losing it''.

``No, it was just self-control we had to learn,'' Goodyer said.

Mr Marron said the ``inadequate training'' given to Goodyer was disturbing.

It is not the first time staff training at Ashley has come under the spotlight.

An inquest into the death of an Ashley inmate is due to hand down its findings in August while a 2007 parliamentary inquiry in to Ashley found there was a lack of trained staff and low morale among its workforce.

In its report it said management struggled to maintain a well-trained, professional and committed staff.

Western Tiers MLC Greg Hall, who was chairman of the inquiry, said at the time Ashley management had been ``divorced from what actually happens there''.

`` Anecdotally, I still hear sometimes that divide is still there,'' he said yesterday.

Children and Youth Service's director of operations Mark Byrnes has defended the facility's training procedure.

``While some staff at Ashley may have previously worked as security guards in previous employment, all staff involved in the engagement of young people are first and foremost qualified youth workers, who as part of their qualifications receive instruction on how to deal with young people appropriately, including in confrontational situations,'' he said.

``The incidence of assault against any young person in Ashley is extremely rare and is treated with utmost seriousness by Children and Youth Services.''