Manager Joe Girardi said Sabathia initially felt the pain two days after his start against the Mariners on Aug. 3 and that it went away but crept back again.
"He had a stiffness, had a test, the MRI revealed nothing," Girardi said. "The stiffness went away. [He] threw again in Detroit and the stiffness came back a couple days later.
"It's not any worse than it was after the first start, but our concern was that it didn't go away. As far as concern, it's pretty low."
Girardi expects Sabathia, who will undergo another exam Monday, to come off the DL when he is eligible to return on Aug. 23 and then start the next night against the Indians.
Sabathia was slated to start Monday against the Rangers and tried his best to avoid going on the DL, said Girardi, but the team did not want to take any chances. The southpaw will speak to reporters about the injury on Sunday.
As of now, Sabathia is not scheduled to undergo any further tests, such as an MRI, but Girardi said there is a possibility he could get a cortisone shot to help with the pain, something he described as common.
Girardi contemplated a couple options but ultimately felt that a DL stint would be the most effective way to eliminate the inflammation.
"The MRI came back good and it is not like it got worse. It just kind of stayed the same, the inflammation came back," Girardi said.
One of the other options was to skip his next scheduled start, but the Yankees passed on that because it still would have required Sabathia to throw this upcoming week.
"I was a little bit concerned, but he didn't express anything. He didn't have any symptoms before the game [today]," Girardi said. "We were trying to prevent [a trip to the DL]. The treatment that he has had over this time has responded OK, but the fact that it came back concerned us."
Had it been September or October, Girardi said Sabathia probably would have pitched, and the fact that he threw well through the pain was an encouraging sign.
While an Aug. 8 outing in Detroit was Sabathia's last start, he threw on flat ground on Friday in Toronto. Speculation had grown prior to Saturday's game that Sabathia's elbow was bothering him after he was seen icing his elbow, but Girardi initially downplayed the significance of it.
Sabathia had already spent time on the shelf in late June and into early July with a Grade 1 left groin strain.
In five starts since coming off the DL, Sabathia is 3-0 with a 3.89 ERA. He has struck out 35 batters and walked just six in 34 2/3 innings of work over that stretch.
Sabathia is 12-3 with a 3.56 ERA over 20 starts this season.
"We are going to have to deal with it, that's the bottom line," Girardi said. "We don't want to, but we need to have him healthy."
Sabathia joins Mariano Rivera, Alex Rodriguez, Andy Pettitte and Brett Gardner on the DL, among others.
Girardi would not speculate who would take Sabathia's turn in the rotation, but there are reports indicating that right-hander David Phelps, who has been pitching out of the bullpen, will get the vacant rotation spot. Phelps has made three starts with the Yankees this season and was a starter his entire Minor League career.
Veteran Derek Lowe, who was released by the Indians on Friday, has agreed to a contract with the Yankees and will pitch out of their bullpen. The deal is expected to become official prior to Monday's game.