Sagna is in Italy for the vital Champions League Play-Off where Arsenal will begin life without Nasri.
"We have lost great players and friends in Samir and Cesc but life goes on," Sagna told arsenal.com.
"Arsenal is still alive and I think we are all confident we can win something and be successful. Now we just want to focus on the games we have to play - we just have to play game after game and focus on ourselves.
"I just want to wish them good luck and they wish us good luck as well."