Harlequins legend Jason Leonard has tipped Irish prop Mike Ross to continue his rapid transition from Premiership novice to seasoned international performer.

The 28-year-old tighthead has been one of the pack's star men over the past 18 months, since signing his first professional contract.

Director of rugby Dean Richards expressed surprise that the former Cork man wasn't picked for Ireland's Six Nations' squad.

Ross finally received a call-up to the Ireland A squad on Friday and Leonard, capped 114 times for England in the front row, has been impressed by Ross' transformation in to a top performer in the trenches.

"I believe we have got one of the best league's in the world in the Premiership. It is a great breeding ground for international players," he said.

"Front row is an uncompromising position and, in the Premiership, you are measured on the forwards.

"Prop is the one position where you have a very intense one-on-one collision every time you pack down for a scrum.

"You get found out very quickly if you are not up to it. Mike Ross has proved his ability very quickly in a very hard league."

But Leonard believes Richards will have to recruit astutely to turn Quins into a Heineken Cup force.

"Quins have the makings of a very good pack, but like most clubs will have to add a couple more faces over the summer to keep progressing," he added "They qualified for Europe ahead of schedule and that has shown a little bit in the forwards. I'm expecting them to change that next season."