The Celtic attacking midfielder was speaking after the Australian returned to Hoops action at the weekend.
The Celtic midfielder was spotted training with his teammates at Lennoxtown on Wednesday.
The Celtic manager has provided information on Mikey Johnston, Marian Shved, Tom Rogic and Vakoun Bayo.
A number of Celtic players, including Tom Rogic, Scott Sinclair and Kieran Tierney have reportedly been attracting interest from other clubs.
Celtic midfielder Tom Rogic has been linked with a move away from Parkhead recently.
Celtic attacking midfielder Tom Rogic is reportedly attracting plenty of attention this summer.
Russian Premier League winner Sardar Azmoun has been linked with Scottish Premiership champions Celtic since 2017.
Celtic will be dealt a massive blow if they lose Tom Rogic to Zenit St Petersburg but they can soften it by demanding a player plus cash in exchange.
Ryan Christie is well equipped to be Celtic's next Tom Rogic.
Scottish Premiership champions Celtic are reportedly in danger of losing Rogic to Russian Premier League champions Zenit St Petersburg.
Leeds United signed Eddie Nketiah and Ben White on loan from Arsenal and Brighton and Hove Albion respectively in the summer transfer window.
Rangers had a pretty busy transfer window with their standout purchase being winger Ryan Kent.
Tottenham Hotspur attacker Erik Lamela failed to have the desired impact after being brought off the bench against Olympiacos.
Dele Alli endured a difficult night in his first start for Tottenham Hotspur this season, as Mauricio Pochettino's side let a two-goal lead slip against Olympiakos in the Champions League.
Chelsea midfielder Ross Barkley missed a crucial spot kick against Valencia, as Frank Lampard's side slipped to defeat.
Who is better right now? Manchester City's Premier League superstar Raheem Sterling or Liverpool's Egyptian King Mo Salah?
Tanguy Ndombele proved his worth in the Champions League with Lyon last season and now he will be hoping to replicate that form when he makes his European debut with Tottenham Hotspur on Wednesday night.
Fikayo Tomori made his Champions League debut for Frank Lampard's Blues but Rodrigo Moreno scored the winner at Stamford Bridge.
Liverpool lost 2-0 away at Napoli on Tuesday night.
Liverpool are currently five points clear at the top of the Premier League table, with Manchester City's injury crisis worsening.
Southampton are reportedly keen on signing the Celtic ace, but West Ham United could steal march on their Premier League rivals.
Celtic have done some excellent pieces of business since the inception of the January transfer window.
Celtic swept aside a poor Motherwell side in the Last 16 of the Betfred Cup, winning 5-0.