IT is a brief, almost pre-season era but it forms the age of anxiety for managers such as Neil Lennon.

There will be protestations to the contrary in the relatively calm surroundings of press conferences but Celtic's season pivots on games such as last night in Sweden.

Any sceptics about this assertion should be referred to photographs of the Celtic manager after his side reached the play-off round for the Champions League. They say a picture is worth a thousand words. The post-match images of Lennon could be covered by two: relief, joy. The Northern Irishman approached this year's campaign with less apprehension than the last and his emotional stability was justified. There was anxiety in Sweden last night, but it was fleeting. Elfsborg were physically fit, sound in shape but limited in launching attacks and unable to finish them. They were, in short, the Mo Bangura of teams.

It must be said that the Sierra Leone forward was the Swedes' best player over the two legs and caused Efe Ambrose problems. An overhead kick and a header in the first half caused an intake of breath on the visitors' bench but he first bounced past and the second flew over. This is trademark Bangura and no one had to be treated for the effects of shock.

Celtic, then, had to guard against their own failings rather than blunt a razor-sharp Elfsborg. Some flaws are obvious. The speedy, confident Emilio Izaguirre 2010 has been abducted and replaced by his feckless twin Izaguirre 2012 /2013. Ambrose is prone to a mistake in the same way that Lindsay Lohan is prone to a meltdown, though the Nigerian's excesses can be more garish. Kelvin Wilson's mind seemed elsewhere - possibly in Nottingham - when he was reckless with a tackle in the box. Anthony Stokes showed in the briefest of cameos that he is not a striker who is fully intelligent at this level, prone to stray offside and careless in possession.

The rest, though, was as comfortable as a European night away from home can be. The result was also perfect. Celtic have now gone seven consecutive matches in the Champions League qualifiers without conceding a goal. This is a highly impressive statistic and Fraser Forster, the team's excellent goalkeeper, was not overworked in enhancing it last night.

The combined attributes of the Celtic side were more than enough to stifle any threat from the energetic Swedes. Joe Ledley and Scott Brown lack the killer pass but they squeeze space and harry their opponents. These traits may founder on the rock of Andrea Pirlo but they are more than enough to frustrate Anders Svensson.

Mikael Lustig, too, is a strong and enterprising full-back whose run in the first half should have taken Lennon's age of anxiety and replaced it with pipe, slippers and a read of the paper after half-time. His burst to the bye-line was matched by a good cross and Georgios Samaras headed over when it was reasonably expected he would head it into the net. Lennon's nodding movement on the bench was an unwitting guide to the Greek striker as to how to apply the finishing touch. Instead, Samaras was left to use his head as a resting place for his hands.

The other major Celtic chance was when Ledley was thwarted by an excellent save from Kevin Stuhr Ellegaard as the ball broke from a defensive wall. Other than these opportunities it was Celtic's task to keep a collective nerve and this they did with some ease.

The advance to tomorrow's draw is a source of unmitigated contentment for everyone associated with the club but Lennon, as ever, flies home with decisions to make. Wilson seems off to Nottingham Forest and the search for a striker continues. The stakes on the next round - where Celtic will face either Austria Vienna, Legia Warsaw, NK Maribor, Ludogorets Razgrad or Shakhter Karagandy - are high.

Lennon has Virgil van Dijk to replace Wilson, and Lustig and Mulgrew can fill in, too. The priority must be a striker. Samaras has a good record in Europe and his height and pace make him troublesome but Lennon's search for a forward will be continued with some urgency and perhaps with an increased budget.

The group stages routinely carry a £20m reward and they would invigorate the season for the Scottish champions. This reality may be enough for Celtic to invest heavily in a goalscorer. One touch can be worth tens of millions at this stage and Lennon knows it.

It is why he bowed his head at the miss by Samaras and it is why he kept Stokes, a regular and reliable goalscorer in domestic games, on the bench last night. With James Forrest and a fit Derk Boerrigter providing pace and guile on the wing, there is a probability that chances will be created and Celtic need someone who can find space with his movement to apply the finishing touch.

However, Celtic fly back to Glasgow and then on to Dublin with the lucrative business end of football's most lucrative club competition still on the horizon . The Champions League group stage is two matches away for Celtic. It may only be 180 minutes but history suggests it will be an age of draining anxiety.