Westermann has urged his teammates to keep up the level of performance that saw the club beat Bundesliga champions Borussia Dortmund 4-1 away at the weekend.
"The attacking tactic suits us well," Bundesliga.com quotes Westermann as saying. "We do not have many defensive players on the field, so we need to find the way forward.
"One thing is clear: we will not be able to put four goals past every opponent. However if everyone wants to have the ball and we all want to play football, just as we did against BVB, then we will always play well on the day.
"The next game against Borussia Monchengladbach will be very hard work. Gladbach are very disciplined and use the ball well, and we need to keep up our level of performance."
Westermann has made 84 league appearances for Hamburg since joining in 2010.