Dortmund won the Champions League in 1997 and topped their group with ease earlier in this season's competition but they will need a much better display against dangerous Shakhtar than the one they served up on Saturday.
"It was a very painful defeat because we should not be letting in four goals at home," Sahin told reporters.
"We can make it all good again on Wednesday but we have to be very focused because Shakhtar are a team that will punish us if we make mistakes.
"There has to be a marked improvement in our performance," added Sahin who returned to the club last month following unsuccessful spells at Real Madrid and Liverpool.
The last 16 tie against Shakhtar is even more significant for Dortmund who won the Bundesliga in 2011 and 2012 and are highly unlikely to make it a hat-trick of titles now that they trail leaders Bayern Munich by 15 points.
The Germans travel to Ukraine without Kevin Grosskreutz who is nursing a suspected lung infection.
Fellow midfielder Ilkay Gundogan is also doubtful after missing Saturday's game with a thigh injury but coach Juergen Klopp will have defenders Neven Subotic and Marcel Schmelzer available again after they missed the Hamburg debacle because of injury.
BAD DAY
"Saturday was just one of those bad days. Wednesday will be a different story, things will be better," said Klopp.
Shakhtar are going into the knockout stage without any match practice due to a three-month winter break in their domestic league.
The Ukrainian champions are used to that sort of schedule though and it did not affect them in 2011 when they beat AS Roma at the same stage en route to the quarter-finals.
Shakhtar are sure to miss influential Brazilian midfielder Willian who was one of the best players in the group stages but elected to join big-spending Russian club Anzhi Makhachkala two weeks ago for a fee of 35 million euros.
The Donetsk team will now pin a lot of their hopes on Willian's fellow countryman Taison.
The Brazilian, signed from Ukrainian rivals Metalist Kharkiv for 20 million euros, has tremendous skill and speed and should fit Shakhtar's style of play perfectly.
"We knew it would be difficult to hold on to Willian and it is hard to say if Taison will be as good as him," said coach Mircea Lucescu. "He will need time."
Probable teams:
Shakhtar Donetsk: Andriy Pyatov; Dario Srna, Yaroslav Rakitskiy, Olexandr Kucher, Razvan Rat; Fernandinho, Tomas Huebschman, Alex Teixeira, Taison, Henrikh Mkhitaryan; Luiz Adriano.
Borussia Dortmund: Roman Weidenfeller; Lukasz Piszczek, Mats Hummels, Felipe Santana, Marcel Schmelzer; Sebastian Kehl, Nuri Sahin, Jakub Blaszczykowski, Mario Gotze, Marco Reus; Robert Lewandowski.
Referee: Howard Webb (England).
