Speaking to reporters for the first time since he broke a bone in his left hand on June 10, Cervelli said he expects to get the soft cast removed Monday.
The injury came less than a month after he agreed to a three-year, $31 million deal through the 2019 season.
"It's a little bit of a nightmare," Cervelli said. "I feel a little embarrassed because of the confidence they showed me with the contract and everything."
Cervelli is expected to miss at least three more weeks after he underwent surgery last week to repair a fractured hook of the hamate bone in his left hand. He suffered the injury while swinging in a game against the St. Louis Cardinals.
"I knew something was wrong," Cervelli said. "I heard something pop in there. I didn't know it was a bone."
Cervelli joined the team for the first time since the injury at Wrigley Field on Friday to start his treatment and rehab.
"They're going to get me back really quick," Cervelli said about the Pirates' trainers. "Right now, I've got to stay focused on getting healthy so I can help my team."
Cervelli is hitting .257 with 21 RBIs in 49 games this year with the Pirates. Last season, he appeared in a career-high 130 games.
Information from The Associated Press was used in this report.