The duo were installed as Leverkusen's management duo in April of last year, but Hyypia has also revealed his concerns about the arrangement.
"It is not easy to live that day in day out. It might be a good short-term solution. But in the long run it also makes things more difficult," Lewandowski told Aktuelles Sport Studio.
Hyypia added: "The arrangement is not easy for either of us. We must compromise a lot, which does make it a bit more difficult. I need to discuss things with Sascha first before making a decision.
"Usually we go into the office to discuss things. We come up with an opinion to which we stick 100%."
Leverkusen face Bayern Munich in the league at the weekend.