SAN FRANCISCO -- A handful of Brewers reserves suddenly find themselves playing a more prominent role for a team that says it still has postseason aspirations.

Veteran Cesar Izturis is Milwaukee's new starting shortstop after Alex Gonzalez was lost Saturday to a right knee injury. And Travis Ishikawa will get significant starts at first base with Mat Gamel sidelined by a knee injury of his own.

In the pitching department, Marco Estrada has already moved from the bullpen to the starting rotation to replace injured left-hander Chris Narveson.

The changes are a big test of the Brewers' depth.

"That's what I'm here for," Izturis said. "I feel sorry for Alex and for the team. He was a big part of the team so far."

Gonzalez will undergo an MRI scan on Monday in Milwaukee. His departure from Saturday's loss marked the fourth straight game in which the Brewers lost a player to injury. Three of those players landed on the disabled list.

"I've never seen something like this," Izturis said. "I've been in this game for a while."

Izturis has dealt with injuries himself, most recently a right elbow injury that cost him most of last season with the Orioles. The year before, Izturis started 142 games for Baltimore at shortstop.

He signed a Minor League deal with Milwaukee over the winter and won a job as a backup infielder. Now he'll adjust back to a starting role, with Roenicke planning to rest Izturis when he deems it necessary.

"I think I'm ready for it," Izturis said.

Counsell has no plans to return to field

SAN FRANCISCO -- Alex Gonzalez had barely made it off the field Saturday after suffering an apparently serious right knee injury before the Craig Counsell questions started rolling in. Might the popular Counsell come out of retirement to help the Brewers get through their wave of medical maladies?

Counsell said the thought crossed his mind, but the answer for now is no.

"I don't have plans to play," he said.

Counsell, 41, was hired over the winter as a special assistant to general manager Doug Melvin and has been working on a myriad of projects, the beginnings of a possible future career as a GM. He has not formally filed retirement papers with the Players' Association, but said players rarely do until they are much more advanced in age.

Because he knows shortstop so well, Counsell was particularly sad to see Gonzalez go down.

"Everybody knew he was pretty good on defense, but it was fun to watch him play shortstop," Counsell said. "He can really play."

Green makes first big league start at first base

SAN FRANCISCO -- After Mat Gamel's big break as the Brewers' first baseman was cut short by a knee injury, it's Taylor Green's turn.

Like Gamel, Green is a left-handed hitter coming off a stellar 2011 season at Triple-A who has primarily played third base. Green was promoted to Milwaukee on Sunday and made his first Major League start at first base, a position he played 23 times in the Minors, including only twice in 2012.

"I'm really excited," he said. "I've taken ground balls over there. I feel comfortable and I'm ready to go."

Manager Ron Roenicke said he would use a combination of Green and Travis Ishikawa against right-handed pitchers and would mostly play switch-hitter Brooks Conrad against left-handers.

That means an opportunity for one player to step up and replace some of the offense lost to significant knee injuries suffered by Gamel and shortstop Alex Gonzalez.

Green was running partially on adrenaline Sunday after his second 4 a.m. wake-up call in three days. He traveled with Triple-A Nashville to Albuquerque early Friday morning, then from Albuquerque to San Francisco on Sunday. He arrived at 7 a.m. PT on Sunday, in plenty of time for the Brewers' 1 p.m. PT game.

Last call

• Brewers principal owner Mark Attanasio indicated he was "getting closer" to contract extensions for both GM Doug Melvin and manager Ron Roenicke. The topic has been under discussion since March.

• If the Brewers go outside the organization for a first baseman, the most well-known free agent may be Derrek Lee. FOXSports.com's Ken Rosenthal speculates that Lee would seek a contract similar to Johnny Damon's deal with the Indians for $1.25 million plus $1.4 million in incentives.

• The Brewers formally made the roster moves on Sunday they preliminarily announced the day before. Alex Gonzalez and Carlos Gomez were placed on the 15-day disabled list. Taylor Green was called up from Triple-A Nashville. Shortstop Edwin Maysonet's contract was selected from Nashville. To make room for Maysonet on the 40-man roster, the Brewers shifted Mat Gamel to the 60-day DL.