CELTIC defender Efe Ambrose is believed to be a target for German Bundesliga side Bayer Leverkusen.

HeraldSport understands the Nigerian centre-half is high up on the BayArena side's wanted listed with representatives in Germany signalling ahead of a campaign in the Champions League that a £1.5m bid may be forthcoming.

The 27-year-old currently has a year left to run on his contract at Parkhead but Celtic will be reluctant to part with Ambrose without having someone coming in to replace him quickly ahead of a crucial stage of their season.

Read more: Sturm Graz 0 Celtic 1: Familiar feeling provides comfort for Rodgers as Celtic's outlook changes

The Ladbrokes Premiership winners begin their Champions League qualifiers next week without Dedryck Boyata, Jozo Simunovic - who are both injured and Charlie Mulgrew, who is yet to agree a new deal.

There was no sign of Ambrose yesterday as Celtic won 1-0 away to Sturm Graz in what was their second game of their pre-season training camp. Visa issues have halted the centre-half meeting up with his team-mates who have flew out to Maribor on Monday night.

"We’re still waiting to hear on whether he’ll be here," said Brendan Rodgers, the Celtic manager after Sunday's victory. "We’re just waiting on that.

"Well, having as many players as possible helps. But the boys who are out here are doing very well. We talk about the aggression in our defending and I was pleased with our corners tonight.

"We talked about having that bit of steel when we’re under pressure from a set piece.

"We defended that well, had good organisation. And, all round, our central defenders are coping well."

A Ryan Christie first half goal proved the difference at the Merkur Arena as both teams fielded experimental line-ups either side of half-time.

"I was really pleased. I thought the first half was great," said Rodgers. "We have spoken a lot about our defensive organisation and we pressed very well.

“Nadir Ciftci did well up front, we pressed well in midfield and on the sides. As soon as we scored, we won the ball back and almost scored again – catching them by surprise. There were large elements of the first half that I was really pleased with.

“The grass was a bit long and it was difficult to pass it, but we still did well on that front. Saidy [Janko] was excellent at right-back. He’s been out a long time and he was like a train on that side – he was solid.

“We have been talking about having 11 players in the team but having one brain. We want to defend together and attack together – and it was another step forward."