PHILADELPHIA -- The Phillies cannot wait to get Bryce Harper back in the lineup.

They need his bat.

The more offense, the better, especially with Sunday¡¯s news that right-hander Seranthony Dom¨ªnguez has been placed on the 15-day injured list with tendinitis in his right triceps, and right-hander Corey Knebel will not pitch again this season because of a torn capsule in his right shoulder. Knebel has been placed on the 60-day injured list. Triple-A Lehigh Valley right-hander Tyler Cyr was added to the 40-man roster and took Dom¨ªnguez¡¯s spot in the bullpen.

Dom¨ªnguez and Knebel are two huge losses for a bullpen with the 11th-best ERA in the Majors (3.71) since June 3.

Phillies interim manager Rob Thomson said he hopes Dom¨ªnguez is back on Sept. 2, when he is first eligible to be activated, although Dom¨ªnguez still needs to take an MRI exam to see if there is any structural damage. Dom¨ªnguez had Tommy John surgery in 2020. This is his first full season since the surgery.

Sept. 2 could be Harper¡¯s highly anticipated return, too. Harper, who broke his left thumb on June 25, said Sunday that he hopes to return around Sept. 1, when the Phillies are on a six-game road trip in Arizona and San Francisco.

The Phillies play Arizona from Aug. 29-31. They play San Francisco from Sept. 2-4.

¡°It¡¯s always a goal to have in mind, where you want to be and what you want to do,¡± Harper said. ¡°But we don¡¯t know until I play. We can all talk about when and where, but we just don¡¯t know until I play and how I feel with contact and things like that.

¡°I¡¯m going to be smart with it. I¡¯m going to be very smart with it and come back when I see fit and when my hand is feeling better and I can help this team every day and not just play two days, one day off, play two days, one day off. I¡¯m going to come back at full strength playing.¡±

Harper said he expects to begin a rehab assignment Tuesday or Wednesday with Triple-A Lehigh Valley.

It is unclear how many games Harper will play in Lehigh Valley. For comparison¡¯s sake, Jean Segura played eight rehab games with Lehigh Valley before he returned from a broken right index finger on Aug. 4.

Harper said, ¡°It¡¯s going to be touch and feel because, I mean, I¡¯m not really sure how it¡¯s going to feel after I make contact, things like that. BP, machine, it all feels good, but you just never know until you get in the game.¡±

Harper said his thumb has responded well since he started to take BP last week.

¡°I¡¯m getting a lot better,¡± he said. ¡°The more I hit, the more I use it, it¡¯s getting better. I think we¡¯re happy where we¡¯re at right now. We¡¯ll just progress as we see fit.¡±

¡°Probably anywhere from 85-90 percent right now, I would imagine,¡± Harper said about the thumb. ¡°I think our biggest thing is the [mobility] of it, I guess, isn¡¯t there. That¡¯s why I say 85, somewhere in there, just because of the [mobility] part of it. But I think the strength and everything like that is there. I think as we progress it¡¯s going to get better and better, I hope.¡±

Dom¨ªnguez was 6-4 with a 1.64 ERA and nine saves in 46 appearances. He had a 2.3 WAR, which was the sixth-best mark on the team, according to Baseball Reference. Knebel was 3-5 with a 3.43 ERA and 12 saves in 46 appearances.

Thomson used Dom¨ªnguez in the team¡¯s most high-leverage situations in the late innings since early June.

Those innings will go to David Robertson -- who pitched a six-out save Saturday -- Brad Hand, Jos¨¦ Alvarado, Connor Brogdon and Andrew Bellatti. Sam Coonrod just rejoined the bullpen after missing the entirety of the seasons so far with a shoulder injury. He could work himself into that role, too.

¡°Just try to mix and match with those guys as the 7, 8, 9 [inning] guys,¡± Thomson said.