MICHAEL STEWART has sent a transfer warning to Ange Postecoglou after the Hoops boss secured a triple signing from Japan at the start of the January window.

The Parkhead club confirmed on Friday morning that forward Daizen Maeda, 24, will join from Yokohama F. Marinos, initially on loan until the end of the season but with a compulsory purchase clause included which will see him sign a long-term deal.

In addition, midfielder Yosuke Ideguchi, 25, will arrive on a four-and-a-half-year deal from Gamba Osaka and the versatile Reo Hatate, 24, will check in from Kawasaki Frontale, also on a four-and-a-half-year contract.

Postecoglou knows the Japanese scene well following his three years in charge of Yokohama before he took over at Celtic last summer, and he is confident the three players can all thrive in Glasgow.

Stewart agrees that the trio of signings are top transfers for Celtic but he insists he would like to see a core of Scottish talents in the Hoops starting XI.

Speaking on BBC Sportsound, he said: "For me there is no question that Ange Postecoglou, and for a lot of people, has caught them by surprise.

"He's come from Australia and Japan, and whenever you spoke to everyone it was very favourable.

"When you consider where Celtic were, they were a basket case in regards to the end of last season.

"He has rejuvenated them, he has brought back to life some of the players who were struggling, and in Kyogo he has brought in a star.

"The guys he has brought in from Japan, by all accounts these are good signings, but I just think there has to be a little bit of an identity with Celtic.

"Under Brendan Rodgers and in the recent past, they have had a lot of domestic players.

"That helps the national side, and I don't want to see that being discarded, to a certain extent.

"With more and more Japanese players coming in, which is clearly a market you would look to exploit because he knows it so well, I think I'd be keen to see the youth and domestic players kept in as well.

"The challenge for them is as the standards are raised they need to keep reaching that bar as it increases.

"The big takeaway is we are halfway through the season, and I don't think anyone wouldn't suggest that Ange Postecoglou looks like a very good acquisition for Celtic at this stage."