Tough call. Irabu is tanking and Zimmerman will be back soon, and Wickman's arm is cause for concern. Stewart may or may not be Montreal's primary closer, and the situation in Milwaukee depends on how Leskanic looks when he returns.
Stick with Julio, keep Wickman for now, but keep an eye on his arm, and drop Irabu for Escobar. If you have a disabled list, grab Leskanic before Escobar and park him on your DL for the time being.