WHAT would Ronny Deila give for Celtic to display the sort of defensive dependability which Italian teams were renowned for in years gone by here in the San Siro this evening?

The Norwegian's side have, in the last few months especially, impressed with their attacking play both domestically and in European competition this season.

In the first leg of this Europa League last 32 tie against Inter Milan at Parkhead last Thursday, they created a plethora of opportunities in the final third and scored three times.

Yet, the Celtic rearguard was once again suspect. Even Craig Gordon, whose heroics in goal effectively ensured the Scottish champions reached the knockout stages, performed poorly.

Jason Denayer, Emilio Izaguirre, Adam Matthews and Virgil van Dijk gifted Roberto Mancini's side easy chances and were punished ruthlessly for their slack play.

Deila's charges will have to excel defensively if they hope to claim what would be a memorable victory - only the second by a Scottish club on Italian soil - over Inter and progress.

The Celtic manager, though, is conscious of this costly failing in his side and has worked specifically in training at Lennoxtown this week on this vital area.

"I think we showed in the match on Thursday that it (beating Inter Milan in Italy) is possible," he said after a final training session in the San Siro last night.

"I have seen the last three or four of Inter Milan's matches and we have a good chance to create chances. It is up to us to be clinical when we create chances.

"I think we have played some good matches away in Europe this season. We did well in Zagreb and we played a good game against Maribor and should have won that game.

"So some of these things we have to take with us. We are in good shape now and have good confidence. We did fantastic in the first game with Inter."

Deila added: "But we need to defend better. We need to close them down when we have that possibility. We have to play more as a unit in the back four.

"We have to be ourselves. That is important. But we also have to be a little bit more conservative in attack and play with a little more balance.

"The game is 90 minutes. We only need one goal if we don't concede anything. So we have to have different plans whatever the result is.

"I saw what happened in the first leg. We are going to produce chances if we continue with the same things. But there are some defensive things we have to get rid of.

"We were too wide in the defence. We have to be more compact in the centre of the pitch. Midfield was quite good I think. But we need to be more disciplined in the back four."

Deila is convinced Van Dijk, the 23-year-old who has not hidden his ambition to play at a higher level, will show what an accomplished defender he is against Inter Milan.

The Dutch centre half is seldom seriously troubled by opposition strikers in the SPFL Premiership. At times, he appears to stroll through games without so much as breaking sweat.

The step up to the Champions League or the Europa League, however, has seemed to be too great for him on occasion in the past and he has often been at fault for goals.

The same can be said of his fellow centre back Denayer, the 19-year-old who is on a season-long loan from Manchester City, on the European stage.

The pair, though, retain the full confidence of their manager who expects them to cope with the considerable threat posed by Argentine striker Rodrigo Palacio and his team mates.

"These are the most important games for them to play in," said Deila. "They are young players both of them. But they can show where they are right now.

"We don't get punished so hard in the Scottish league because we have 70 per cent possession in almost every game.

"When the pressure is on you that is when you need to show yourself. In Scotland, he (Van Dijk) goes out and plays the game and that is what he needs here. It is about having the right focus.

"Virgil is more than good enough to be a top player at that level. He is a top player at this level and it is just a matter of relaxing and doing the same things he does in Scotland."

Deila travelled to Italy earlier this month to watch Inter play Palermo in a Serie A match in the San Siro and appreciates the magnitude of the task that awaits Celtic this evening.

The 39-year-old, who was headhunted after impressing with Stromsgodset in his homeland, believes experiences like this one will aid his development as a coach.

"It is my biggest challenge so far," he said. "It is the highest level I have been at as a manager. That is why it is an important game.

"You learn all the time in football. You can talk about being successful and playing like Barcelona but you have to go out and do it.

"You have to experience these sort of things before you know what is expected at that level. I am a young manager from Norway. I am learning all the time and my biggest skill is that I can learn quickly.

"The San Siro reminds me of the Santiago Bernabeu. It is going to be one helluva experience. But it won't be any worse than what the Inter Milan players faced at Celtic Park."

Gary Mackay-Steven, who signed from Dundee United in the January transfer window, acquitted himself superbly in the first leg despite his lack of European experience.

The winger is confident he will cope if he is named in Deila's starting line-up this evening or brought on as a substitute in the course of the 90 minutes.

"I just focus on what I do best and for me that's playing football, he said. "I am the same if it's Inter Milan in the Europa League or an SPFL game.

"I approach it the same way, go out and play my own game and look to show what I can do. I am really looking forward to the game in the San Siro."