SYDNEY (Reuters) -Australia coach Joe Schmidt was impressed with the depth of the British & Irish Lions squad and thinks the Wallabies will have to play their own game if they are to come out on top in the three-test series in July and August.

The New Zealander knows many of the 38 players named last week from his time as Ireland coach but is looking forward to the Lions taking on Argentina on June 20 to get a glimpse of others and an idea of the way Andy Farrell's team might line up.

"I think everything's a contest there," Schmidt told reporters on Monday.

"Some of them I know very well having coached them, but I think some of the lesser-known ones are going to be very interesting.

"And also just to see what combinations the Lions staff are deciding to put together, because that might give us an indication of who we might face in the first test. Because there's a lot of competition for places."

Schmidt said he had been impressed with what he had seen of 20-year-old England flanker Henry Pollock, who was selected for the Lions after playing only 32 minutes of test rugby.

"(He) is a very, very promising player," he said.

"Considering he was playing in the England under-20s at the start of the Six Nations and came through and ended up playing for the senior side, not many players get to do that, particularly not in the forwards."

Schmidt oversaw a marked improvement in the Wallabies last year but said failing to beat Ireland in Dublin last November after leading 13-5 at halftime had taught them a key lesson.

"I don't think that we can come out against the Lions and say, right, let's try to shut the game down," he said.

"They have power, skill, they have speed. So they can play in a number of ways and whatever way they play, we're going to have to try to play our game."

Schmidt said he would select a squad of up to 40 players after all the Australian teams had concluded Super Rugby, but would also release test players back to their teams to allow them to face the Lions in tour matches.

The 59-year-old reiterated that no eligible player, whether they are currently playing overseas or heading offshore at the end of the season, had been ruled out of selection for the series.

He said he had been in touch with overseas-based lock Will Skelton, centre Samu Kerevi and winger Marika Koreibete, who all played tests last year, as well as flyhalf James O'Connor, who is playing Super Rugby in New Zealand.

"We don't want to discount anyone because, as Andy's done, we'd love to pick a form squad," he said.

"But as I've always said, if there's anything that we think is 50-50, it's more difficult to absorb someone in from outside of the groups that play together already. It's just not the same cohesion."

(Reporting by Nick Mulvenney, editing by Peter Rutherford)