"I just can't rule it out," Cashman said. "We've got to do what's right for him. Whatever is right for him, it will be right for us."
Jeter is expected to rest for at least the next few days following the injection, which was administered by Dr. Daniel Murphy in Tampa. Jeter was scratched from Tuesday's lineup against the Phillies and was not at George M. Steinbrenner Field for Wednesday's 4-0 win over the Red Sox.
"It's a little setback, but we'll get through it," manager Joe Girardi said. "What it means for today, tomorrow, the next day -- I can't tell you. But we'll get through it."
The Yankees have not fielded an Opening Day lineup without Jeter since 2001. In that game, Luis Sojo started at shortstop in place of Jeter, who was on the disabled list with a strained quadriceps.
CC Sabathia said that he has texted Jeter to wish him good luck, but New York's ace did not seem surprised that the team is uncertain about Jeter's availability for the opener.
"I mean, he broke his ankle less than six months ago," Sabathia said. "Would you like to have him out there? Of course. But realistically, if he's not, I think him being healthy in the long run is what we look for. Being healthy Game 1 of the playoffs or October is better than him being healthy for Opening Day."
Jeter's longtime teammate, Andy Pettitte, said that he knows Jeter is frustrated and that there will be a symbolic meaning if the team can see Jeter's name in the lineup on April 1.
"Hopefully whatever Derek has going on, the shot will calm it down and help him with that," Pettitte said. "I look forward to seeing if that helps him and he's able to get back out there. He had a pretty serious surgery on his ankle, so it's going to take a little bit of time, especially running around out there at shortstop."
Time is not something that the Yankees have an abundance of. Cashman said that the club needs to know Jeter can play a full nine innings in the field as well as play in back-to-back games before they would consider him a viable option at shortstop.
Yet because of Jeter's reputation as a gamer, Cashman would not rule out the possibility that Jeter finds a way to be in the Yankees' lineup when the first pitch of the regular season is thrown.
After all, Cashman, Girardi and head athletic trainer Steve Donohue actually had to forcefully tell Jeter that an ankle fracture wasn't something he could play through for the remainder of the ALCS.
"I hate to say it, but no matter what he's up against, he's going to find a way," Cashman said. "He's always found a way. That's just what makes him tick. That's always been our experience with him. That's the entire aura of Derek Jeter: he just finds a way."
If Jeter is unavailable to begin the season, Eduardo Nunez would be the Yankees' everyday shortstop. Cashman said that the club is confident Nunez will be able to handle the job.
"There's a reason Joe Girardi played Nunez at shortstop the entire spring," Cashman said. "It was in the event we ever had any issues, we'd have somebody ready to go. I'm not saying [Jeter] is going to be DL'ed, but I can't tell you he won't be."
It has been a rough spring for the Yankees in the DL department, as outfielder Curtis Granderson and first baseman Mark Teixeira suffered injuries that will keep them out of action at least through April. Alex Rodriguez is also expected to be sidelined until the All-Star break as he rehabs from left hip surgery.
"Injuries are a part of the game, you know?" Sabathia said. "Guys are going to go down. Nobody's going to feel sorry for us. We've got guys in here who can hopefully step up and try to fill the void until these guys come back."