Ronny Deila played down talk of a crisis ahead of Celtic's Europa League Group A opener against Ajax in Amsterdam on Thursday.
Both clubs, previous winners of the competition, missed out on this season's Champions League group stages after losing their respective play-off ties.
Celtic dropped into the Europa League after a 4-3 aggregate defeat by Swedish side Malmo and there is pressure on the Hoops' Norwegian boss Deila to make a better fist of the second-tier competition.
"We are determined to reach our goals, to win trophies and progress in Europe, Deila said.
"Everybody was disappointed not to get into the Champions League and it can take a bit of time to get over it.
"But I think we have cleared the air now and can focus on getting forward. We still have so much to look forward to."
Also in Group A, Fenerbahce take on Norwegian opponents Molde for the first time when they square off in Istanbul.
Bordeaux have won only one of 10 games against English sides in their history and will be hoping for a positive start when they host Liverpool in Group B. Swiss outfit Sion are also in that pool and will be at home to Rubin Kazan.
Borussia Dortmund, back in the group stages after a four-year absence, will be in Germany to face Russian side Krasnodar in Group C. Azerbaijan side Qabala have made it all the way from the first qualifying round to the group stages and will take on PAOK in the other Group C clash.
In Group D, competition debutants Midtjylland open their campaign against Legia Warsaw in Denmark and Napoli have home clash with Club Brugge. The Serie A club are searching for their first win of the season.
Marseille visit Dutch side FC Groningen in their opening Group F fixture and Slovan Liberec go up against Portuguese club Braga, who will be playing their 100th UEFA game.
Viktoria Plzen coach Karel Krejci took over from Pavel Vrba in the summer and is looking to make a positive Group E start against Dinamo Minsk. In the other group game, Rapid Vienna are hoping to clinch their first ever win against Spanish opposition when they host Villarreal.
Rosenborg are unbeaten in their last nine European away games and take on St Etienne in France in Group G. Last season's runners-up Dnipro welcome Italian side Lazio to Ukraine in the other Group G match.
Sporting Lisbon open their Group H campaign at home to Lokomotiv Moscow. No Albanian side have managed to avoid defeat against Turkish opposition, and that is what Skenderbeu are aiming to do in the other Group H match with Besiktas in Elbasan.
Lech Poznan have lost only one of their last 15 European home games and are at home to Portuguese side Belenenses in Group I. New Fiorentina coach Paulo Sousa will have to put emotions to one side when he takes on Basle - the team he led to the Swiss title last season - in the other group encounter.
Anderlecht have won only one of their last eight European home games and lock horns with Monaco in Brussels in Group J. Tottenham are at home to Qarabag in a Group J opener that will see an English side take on an Azerbaijani outfit for the first time in UEFA competition.
Schalke travel to Nicosia to face Apoel in Group K, which also sees Sparta Prague visit Greece to take on Asteras.
The 2012 tournament runners-up Athletic Bilbao are in Group L and host an Augsburg side making their debut in European competition. In the same pool, Serbian champions Partizan Belgrade, who have won all three of their European home games, host AZ Alkmaar for the first time.
