Yesterday he celebrated six years in charge at Bolton - and his 51st birthday - but he is now telling his team to get back to basics.
"The foundation of what we are going to achieve has to come from clean sheets. We need to work on that 'no goals against' basis," said the Bolton manager. "We must not make it too easy for the opposition like we did against Chelsea.
"It is typical of the way football is that we are going into the game on the back of a mini-crisis. When we got to Wigan it was all looking quite rosy. But we have now conceded seven goals in two games after letting in only two in the whole of last month. It gets the alarm bells ringing in terms of things not being right.
"Players' confidence can turn very quickly as we saw only too clearly last season when we went on a losing run."
Allardyce has also been dealt another blow before the first game of the group stage with the Greece winger Stelios Giannakopoulos joining the club's injured list.
Giannakopoulos suffered a groin problem at Stamford Bridge and, along with Jay-Jay Okocha, Gary Speed, Ivan Campo and Nicky Hunt, will remain behind to have treatment at the club.
Allardyce is naturally concerned that so many key players are unavailable for the European game. He said: "I thought we would get injuries but not this early in the season. Gary and Jay-Jay were always going to be doubtful, then Stelios complained that his abductor muscle was troubling him.
"All the travelling may cause the injury to worsen. It is better he stays at home and is, hopefully, 100 per cent when the next game comes around."
While Bolton are enjoying their first season in Europe, Besiktas are seasoned competitors at this level. However, they are in turmoil following the departure of their coach, Riza Calimbay, on Monday.
Allardyce said: "The main problem for us now is we don't know what system they will play. Hopefully, we can cope with a full house and come away with our heads held high."
With Giannakopoulos, Speed and Okocha all missing, Kevin Nolan will have a tough job in midfield to attack and create chances. However, his impressive goals last month against Portsmouth in the Premiership and Lokomotiv Plovdiv in the Uefa Cup prove what he is capable of. Nolan will be up against the Romanian Daniel Pancu, probably Besiktas' most dangerous and penetrative midfielder. He scores goals and is relied upon to take Besiktas' penalties.
Bruno N'Gotty must try to restrain one of the most prolific strikers in Turkey and will need to use his strength on the ground in an attempt to overpower the pacy and skilful Souleymane Youla. The Guinean international, already has a hat-trick to his name in the Uefa Cup this season, in the 4-1 victory over the Swedish side Malmo. Youla produced the hat-trick after Besiktas had suffered a disappointing 1-0 defeat in the first leg.
Another key battle will be between Bolton's El Hadji Diouf, who will want to use his close control and flair to break away and put Bolton on the score sheet, and Adam Dursun.
Diouf's form has been patchy this season, and Dursun is not the type of defender a forward enduring a crisis in confidence wants to come up against. The Turk is equipped with pace and excellent man-marking ability.
Bolton Wanderers (from): Jaaskelainen, Walker, Ben Haim, Jaidi, N'Gotty, Pedersen, Nolan, Fernandes, O'Brien, Speed, Nakata, Gardner, Diouf, Davies, Borgetti, Diagne-Faye, Vaz Te, Fojut, Fadiga.Reuse content