A much tougher away assignment awaits Celtic on Tuesday, when they travel to Austria for the first leg of their Uefa Cup preliminary round tie against Tirol Innsbruck.
"First things first," Jansen said. "We have a job to do against Berwick before the players can think of Europe. I'm confident we will have the right attitude. We only have to carry on from how we played on Wednesday in the 1-0 friendly win against Roma. The Berwick game is another good opportunity to show what we can do - it is an important match for us."
Jansen's main injury concern ahead of the game is the fitness of the French international Stephane Mahe, who has an ankle injury. Regi Blinker, who arrived as part of the exchange deal which took Paolo Di Canio to Sheffield Wednesday in midweek, is expected to make his debut.
Berwick's manager, Jimmy Thomson, hoped the former Celtic goalkeeper, Pat Bonner, would join his side, but the former Repubic of Ireland international rejected the move.
Thomson said: "I'm confident the players I have will we be professional and not let everyone down. I'm not going to stand here and say we will beat Celtic, but the players will do themselves proud."
Dumbarton's manager, Ian Wallace, hopes for the same level of commitment as his side meet his former club, Aberdeen, at Boghead.
"It is a big game for me personally, but hopefully my players can show people that while we might be in Third Division we can play," he said. "I've signed a three-year deal here and intend to see it out. I'm happy that Dumbarton are moving forward and see this as the ideal place to learn the trade of management - with the next lesson tomorrow."Reuse content