BALTIMORE — Bobby Parnell’s rough weekend cost him a spot in the Mets bullpen Tuesday.

According to an industry source, Parnell had three choices presented to him by club officials and ultimately picked the disabled list.

Parnell’s other two options were accepting a demotion to Triple-A Las Vegas or being designated for assignment. Parnell would have to give his consent for a demotion to the minors because of his service time.

A statement released by the club said Parnell went on the DL with right shoulder tendinitis. MLB is not likely to investigate the transaction, according to a source, given there is a gray area because Parnell is coming off Tommy John surgery.

In two losses to the Pirates over the weekend, Parnell — who is 1-3 with a 5.59 ERA in 23 appearances — combined to allow four earned runs over two-thirds of an inning.

Logan Verrett was summoned from Triple-A Las Vegas to take Parnell’s roster spot and was available to pitch from the bullpen.

“[Parnell] went out there and did the best he could under the circumstances,” manager Terry Collins said before the Mets’ 5-3 victory over the Orioles. “I think the time off and I know he’s trying to get back to some mechanical things with [pitching coach] Dan [Warthen], so this will give him an opportunity to square that up without having to jeopardize anything.”

Collins said he’s unsure about the seventh-inning role, but Verrett could be considered. Hansel Robles is also a candidate, and the manager could use lefty Eric O’Flaherty for certain matchups.

Collins had no additional information on Rafael Montero, who suffered a setback in his last minor league rehab appearance and is back to “Square 1,” according to general manager Sandy Alderson.

Earlier this month, Collins met with Montero, who has complained about shoulder discomfort at various points since late April, when he was placed on the DL.

“My whole thing was to let him understand how important he could become in our organization right now,” Collins said. “Where he could fit, the importance of what he can bring to the table and the whole process, every so often you do have to push yourself. There is a difference between stiffness and pain.”

Lucas Duda (1-for-5) was in the starting lineup for the first time in seven games. Duda had battled a lumbar strain in his back.