CELTIC will seek to sign another forward before the transfer deadline that kicks in 24 hours before the Scottish champions play Maribor of Slovenia next week in the Champions League play-off round.

Alexsandar Tonev, the 24-year-old Bulgarian winger, last night passed

a medical and has signed from Aston Villa on a season-long loan deal which could be with a view to a permanent deal for £2m.

However, Celtic have other targets. The club was unable to push any through last night as the transfer window closed for the Maribor tie but clubs are allowed to sign one player up to 24 hours before the kick-off next Wednesday.

It is understood that Celtic hope to add another forward to the squad in time for the ties that could see them enter the Champions League group phase after Legia Warsaw were thrown out of the competition for fielding an ineligible player.

That forward is highly unlikely to be Georgios Samaras, the Greek who left the club in the summer. He is not on the list of preferred candidates.

Tonev is seen as a significant capture because he can play wide or in behind a striker. Ronny Deila, the Celtic manager, has bemoaned a lack of pace and creativity as Celtic lost 6-1 to Legia.

This has led him to turn to Tonev who was scouted extensively by John Park at Celtic before he signed for Villa from Lech Poznan in 2013. The Bulgarian, who has played for his country 15 times, found his opportunities limited under Paul Lambert at Villa. However, he has shown the quality that Deila demands and could be thrown immediately into the fray against Maribor though tomorrow night's match at St Johnstone may come too early for the player,

Celtic's transfer pot has been bolstered after Fraser Forster signed for Southampton at the weekend for £10m, though a significant portion of that is due to Newcastle United as part of the goalkeeper's switch to Glasgow.

There were reports from France last night suggesting Jeff Louis, the Nancy midfielder, was a Celtic target after his move to Standard Liege collapsed. The Haitian midfielder had agreed a £1.75m deal with the Belgian club but the move failed after a disagreement about the structure of the transfer fee. However, Louis, 22, said he would remain in France if the Liege deal could not be resurrected.

Gordon Strachan, meanwhile, believes his former charges have done nothing wrong by refusing to indulge Legia Warsaw and their wish to return to the Champions League play-off round at Celtic's expense.

The Polish champions, who were eliminated from the competition for fielding an ineligible player in their 6-1 aggregate victory, have requested a meeting with Celtic officials to "settle the matter honourably". The Scottish champions, though, have refused to be drawn into the debate, believing it is a matter for UEFA and Legia only. Strachan had sympathy for the Poles' plight but felt that they only had themselves to blame for what he called "a lack of concentration".

"Celtic have no part in this at all," he said. "It's all down to Legia Warsaw themselves. I don't think Celtic complained about it - it came from another source - and that's the rules. Imagine Tiger Woods lining up to take a putt and the ball moves and he addresses it. It's a penalty stroke. His opponent isn't going to say 'I think Tiger is a nice fella so let's just let him away with it'.

"That's the rules and you have to deal with it. Legia Warsaw can't make the rules up. Sometimes rules can be really cruel to you and there's absolutely no doubt they've been really cruel to Legia Warsaw. If Celtic were to agree

to overturn the decision where do we go after that?

Do we just bend the rules depending on high you are up the pecking list in superstardom? If you did that then Pele would be running the whole Brazil side - and he's come away with a few crackers in his time!

"It's not cheating, just lack of concentration. That happens in football. You can tell a player to stand in a certain position at a corner kick and the next minute the ball is in the back of the net and they aren't there. Sometimes a lack of concentration can be from a set play when you're meant to be standing at the back post and you're not there. We lost to England with a lack of concentration at a set play and were punished. The same thing happened with Legia Warsaw."

Strachan recalled a similar situation in 1992 when his Leeds United side were given a route back into the Champions League after Stuttgart, who had knocked out the English champions, were found to have fielded an ineligible player. Leeds then won a play-off game to set up an all-British qualifying tie against Rangers.

"We were 4-1 up after losing the first leg 3-0 so we needed to score another goal," added the Scotland manager. "They put someone on with 15 minutes to go to make it three centre-backs and they held out so that was a wee bit different. It popped up that we could get a replay because that was the rule in those days. We got that and got through 2-1. I'm actually just checking the Artmedia Bratislava team [who beat Celtic 5-0 in 2005] to make sure they were all eligible. I want to wipe that out the memory bank!"