Carlton's young Irishman Ciaran Byrne has hurt his hamstring training and will miss Saturday's ANZAC Day clash against St Kilda in Wellington.

Byrne limped from the oval after straining his hamstring in Wednesday's main training session.

Scans have revealed it's a low-grade hamstring strain, which is likely to sideline Byrne for three weeks.

It's disappointing news for the Blues, with Byrne impressing on debut against Essendon last weekend.

With his parents watching on after making the trip over from Ireland, Byrne gathered nine disposals, one mark and two tackles in just over a quarter of football, after starting as the sub at the MCG.

Coach Mick Malthouse said he had been delighted with the 20-year-old's effort.

"It was fantastic for our football club to see 'Casey' get out there – and he ate it up," Malthouse said.

"When I said to him just before three quarter time 'you're on,' I could just see in his eyes there was no fear – he just wanted to go on and wanted to get the football.

"This setback is disappointing for him and for us, but I'm sure we will see him playing again in the not too distant future."