Both teenage forwards featured in the 0-0 draw with Crystal Palace and Irvine said: "Lukas got on the pitch because there wasn't anybody else.
"It was terrific for Bjarni too. He was out on loan (at Bournemouth) last season and did well. He's close to our first team because we've got injuries and he's been doing well in training.
"He's capable in training and the lads respect him and know the ability he's got so we'll have to wait and see what happens with those two lads, they've certainly been given a taste today and that can only be good for them."