Byrd was hit on the left side of his face Saturday night by a pitch from Boston's Alfredo Aceves. He saw Dr. Jonathan Rosin, a specialist at Northwestern Hospital in Chicago, on Monday and will be re-examined this week.
"The bruising in the retina area is subsiding some, which is good," Hendry said. "Because of the fractures and the bruising in that spot, it's detrimental for him to do any more than walking around for one to two more weeks. That's not surprising, and that's good news because the healing process has started. We'll have to play that by ear."
Hendry said they cannot put a timetable on when Byrd could return.
"For as devastating as it could've been, he certainly will be able to play in a reasonable amount of time," Hendry said.
Byrd was hospitalized overnight on Saturday but was able to fly back from Boston on the team plane Sunday night.
"It was good to see him afterwards and it was good to see him because he's OK, relatively speaking, and that's the main thing," Cubs manager Mike Quade said. "It was a pretty dangerous situation. Nobody will come back from this quicker than he will. I don't know how quick it will be but nobody will come back quicker."
Byrd was the Cubs' No. 3 batter for most of the season, although Starlin Castro has made 16 starts there and was batting third Tuesday as the team opened a homestand against the Mets.
"I'm still happy with the 1-2-3 guys getting on base and doing what they do," Quade said. "We're still getting our hits. I don't think you do any good by sliding guys up who are in the middle and having them hit first or second. We just need production out of the middle of this lineup like everybody in baseball does."