No Bundesliga team has conceded more goals than Hamburg's 38 in 17 games so far this campaign, although their attacking record is the second best outside the top four, with 33 goals to their name.
"The fact we conceded so many goals went hand in hand with the fact that we were prone to losing our concentration," Calhanoglu told the official website of the Bundesliga.
"We actually boast a lot of quality both in attack and at the back. Our preparations have run really smoothly though and as a result we're hoping to be able to pick up a win in front of our home support on Sunday."
Hamburg will resume their campaign against Schalke on Sunday, looking to extend the two-point gap that separates them from the relegation playoff spot.