"We're losing what we felt was a great pinch-hitter last year in Kotsay," Roenicke said. "We're looking at a guy [in Ishikawa] who's got some experience, and he's done a nice job for San Francisco in the Major Leagues."
Ishikawa played 281 games for the Giants since 2006 and is a plus defender at first base who can play left field in a pinch. He's 20-for-75 (.290) lifetime as a pinch-hitter.
He'll be the primary backup to Mat Gamel, Milwaukee's first-year starter at first base.
Both Ishikawa and Conrad were in Brewers camp on Minor League deals. Conrad will play multiple positions for Triple-A Nashville, whose infield is set with first baseman Erick Almonte, second baseman Eric Farris, third baseman Taylor Green and shortstop Edwin Maysonet.
Conrad's calling card was versatility. Without him, the Brewers only have one reserve middle infielder -- veteran Cesar Izturis. Roenicke said the team would "go with this for a while and see how it plays out."
Maysonet impressed Brewers coaches in camp and is only a call away. He has logged big league time with the Astros and has one Minor League option remaining.
The Brewers plan to formally file their 25-man roster before Wednesday's Spring Training finale against the D-backs. Barring a last-minute injury, it will include starters Yovani Gallardo, Zack Greinke, Randy Wolf, Shaun Marcum and Chris Narveson; relievers John Axford, Francisco Rodriguez, Jose Veras, Kameron Loe, Marco Estrada, Manny Parra and Tim Dillard; catchers Jonathan Lucroy and George Kottaras; infielders Gamel, Rickie Weeks, Aramis Ramirez, Alex Gonzalez, Izturis and Ishikawa and outfielders Ryan Braun, Nyjer Morgan, Carlos Gomez, Corey Hart and Norichika Aoki.