The left-handed hitting outfielder, who made his big league debut as a September call-up a season ago, has not played since April 14 and is listed as day-to-day.
"When I dove for the ball, I jammed my thumb on the ground," Fuld recalled. "I tried playing with it for a while. I rested it toward the end of spring training and played with it at the beginning (with Iowa), but it wasn't getting a whole lot better."
Fuld entered 2008 with a career batting average of .300 in three minor league seasons and batted .287 in 104 games a season ago between Iowa and Class AA Tennessee. He was named the Most Valuable Player in the Arizona Fall League and was honored with the Dernell Stenson Sportsmanship Award for his efforts. He batted .402 (43-for-107) in 29 games for the Mesa Solar Sox of the Fall League, leading the league with 43 hits, 11 doubles, and a .492 on-base percentage.
Fuld believes the thumb injury might explain his early struggles this season.
"I think it definitely has effected my hitting," Fuld said. "It hurts to hit."
Upon making his big league debut last September, Fuld played in 14 games (mostly as a defensive replacement late in games). He was hitless in six at-bats, but drew three walks and scored three runs. He said the call-up was a good experience.
"I learned a lot and I think it helped me this spring," Fuld said. "It made the transition a lot easier. Hopefully I can gain something from that call-up for years to come."
Fuld was 5-for-31 (.161) in 21 games this spring with Chicago.
"I could have hit a lot better and played defense better," said Fuld. "I wasn't too happy with it, but that's how it went. If you put it in perspective, it's not the end of the world and hopefully it can be a learning experience."
Fuld was a Cubs 10th-round draft pick from Stanford in 2004. He has Type I diabetes and has to test his blood sugar several times a day while taking insulin shots.
A lot has been written about Fuld's condition, but he doesn't shy away from talking about his diabetes – even though he feels it sometimes might be overplayed.
"I think it might get blown out of proportion in a way," said Fuld. "(But) I know what an inspiration it was when I was young to look at the few major league players that were diabetic. I know how much that meant to me, so I take any opportunity I can get to talk about it, and if I can give any kid some sort of hope, I'm happy to do that."
Fuld is hoping to avoid a stint on the disabled list and return to the Iowa lineup soon. He did not take batting practice in the Cubs' four-game series against New Orleans this week and has been wearing a protective wrap on his thumb.
"It's nothing serious, but you don't want it to be a real nagging injury," he said.