Larsson spent seven years with the Glasgow giants but started and finished his career with the Swedish champions.
Celtic manager Neil Lennon said that despite his close relationship with Larsson, he will not be seeking inside information ahead of their play-off first leg tie in Sweden on Tuesday.
"Henrik will have a foot in both camps and I'm sure his head will be spinning with people ringing him, whether it be from Celtic's side, Helsingborgs' side or the press," said Lennon.
"I'm sure he will be getting inundated with requests for information and interviews. I am going to leave him to it. I wouldn't want to put him in that position. We have plenty of people who will do plenty of homework."
Larsson hit 242 goals in 315 competitive appearances for Celtic during a career which featured two spells with Helsingborg -- first from 1992-93 and then from 2006-09.
Celtic will host the return leg on August 29 with the winners progressing to the group stages along with the nine other victors of the play-off ties.
Germany's Borussia Moenchengladbach are looking to reach Europe's elite club competition for the first time since 1978 but first must get the better of experienced European campaigners Dynamo Kiev.
Moenchengladbach's fourth-place finish in last season's Bundesliga has taken them to within one step of making a group stage debut.
Dynamo reached the play-offs by beating Feyenoord 3-1 on aggregate in the third qualifying round.
In other ties, Spartak Moscow meet Fenerbahce of Turkey looking to reach the group stages for the 11th time.
Danish league runners-up Copenhagen tackle Lille having lost three of their four previous home matches against French visitors.
On Wednesday, Hapoel Kiryat Shmona take on Belarusian side BATE Borisov looking to follow in the footsteps of Maccabi Haifa, Maccabi Tel-Aviv and Hapoel Tel-Aviv and become the fourth Israeli club to compete in the group stages.
Limassol of Cyprus face Anderlecht with the Belgians hoping to end a run of four successive failures in qualifying between 2007 and 2010.
Spain's Malaga tackle Panathinaikos in what could be an intriguing tie.
Panathinaikos coach Jesualdo Ferreira was hired as Malaga boss in June 2010 but lasted just five months before being replaced by Manuel Pellegrini.
Play-offs 1st leg matches
Tuesday
Spartak Moscow (RUS) v Fenerbahce (TUR), Basel (SUI) v Cluj (ROM), Helsingborg (SWE) v Celtic (SCO), Moenchengladbach (GER) v Dynamo Kiev (UKR), Copenhagen (DEN) v Lille (FRA)
Wednesday
Bate Borisov (BLR) v Kiryat Shmona (ISR), Limassol (CYP) v Anderlecht (BEL), Dinamo Zagreb (CRO) v Maribor (SLO), Braga (POR) v Udinese (ITA), Malaga (ESP) v Panathinaikos (GRE)
2nd legs: August 28 and 29
Source: AFP
Source: AFP