"We're not finished acquiring starting pitchers," Hoyer said on Friday. "We want to have as much depth as possible.
"At this point, we're still very much in the process of gathering as many quality arms as we can, and we'll put those pieces in place as we get closer to Spring Training," he said.
The goal is to avoid what happened to the team in 2011, when it lost both Cashner and Randy Wells to injuries after their first starts. Cashner was dealt Friday to the Padres for Rizzo and is expected to pitch out of the bullpen.
"We have worked hard, and we continue to work hard, and hopefully we'll have even more starting-pitching acquisitions," Hoyer said. "We want to go seven, eight, nine deep in the rotation and we hope to replenish the bullpen as well."
The Cubs are still in negotiations with free agent Kerry Wood, who has made it clear that he wants to stay with the team. Wood gave the Cubs a hometown discount last year when he signed a one-year, $1.5 million deal.
"We've had a lot of conversations with Kerry and his agent, Pat Rooney," Hoyer said. "We've all made it very clear that we want to bring him back. We're hopeful that gets done. It's not done yet, and I can't say it definitely will, but it's certainly the Cubs' goal to bring him back here and put him in the Cubs' bullpen."
Although Hoyer wouldn't speculate on the projected rotation, the infield will likely consist of Bryan LaHair at first, Darwin Barney at second, Starlin Castro at short and Ian Stewart at third.
"Any time you go with young players, it's the right thing to do," Hoyer said. "It's exciting to have young talent in the organization. There's no doubt that with young talent comes an adjustment period. The best prospects and players who get through that adjustment period, they take off."
He acknowledged that the growing pains are "something we're prepared to deal with." Hoyer said that the only way to build an organization is to have patience with the players.
"You can do it by constantly acquiring veterans with less upside, but the only way to be a really great organization is to be willing to go through the young players' growing pains to get the reward at the end of the tunnel," he said.