Tomoya Mori left a game against WBC Cuba on March 5 early because he took a pitch off his left elbow during his at bat in the fourth inning. He left the field for treatment and did not return. He told reporters after the game that he was okay.
Mori was examined at a hospital in Osaka today and a fracture was discovered in his left olecranon. He is scheduled to return to Tokyo for additional tests with the team doctor.
[UPDATE 3/29 @ 11:29pm]
Surgery was a possibility, but Mori and the Lions opted for non-surgical treatment. He is slated to begin a rehab program in April. He will most likely require more than two months for a full recovery.
Source: Daily Sports 3/29/2017
[UPDATE 5/6 @ 5:41pm]
Mori tossed batting practice at Seibu 2 Stadium earlier today. He spent about thirty minutes throwing over 150 pitches to Yuji Kaneko and Aito Takeda. Based on his current progress, he might not be ready to return to the active roster until some time after Inter-league play.
Source: Tokyo Sports 5/6/2017
[UPDATE 6/14 @ 2:39pm]
Mori is making slow progress. An examination revealed that the fracture in his left elbow was still not fully healed. There is also a difference in size of two to three centimeters between his arms. He might not be ready to play in rehab games until some time in late-August.
One big reason for the slow progress might have something to do with Mori’s decision to go with non-surgical treatment.
Source: Tokyo Sports 6/14/2017
[UPDATE 7/29 @ 7:09pm]
Mori is taking batting practice against pitching machines and catching Ni-gun pitchers in the bullpen, but has not yet participated in team batting practice sessions. He might still need another half-a-month to a month before he is ready to take the next step. At this point, his focus is most likely the 2018 season.
Source: Tokyo Sports 7/29/2017
[UPDATE 8/8 @ 10:30pm]
Mori entered a Ni-gun game against Nippon Ham as a pinch-hitter in the sixth inning and grounded out to third. It was his first game in about five months.
[UPDATE 8/9 @ 4:58pm]
Mori entered the game as a pinch-hitter in the third against Nippon Ham today. He hit a grounder to second and reached on an error in his first at bat in the third inning and hit a two-out solo home run to left in his second trip to the plate in the fifth inning. He took over at catcher in the fourth and worked two innings.
Added additional performance information on 8/9 @ 8:48pm.
[UPDATE 8/11 @ 11:48pm]
Mori hit a two-run homer against Ni-gun Rakuten earlier today.
Source: Sponichi 8/11/2017
[UPDATE 8/15 @ 8:22am]
There is a good chance the Lions will add Mori to the active roster today. He will most likely be used as either a designated hitter or pinch-hitter, since he has only played one full Ni-gun game at catcher.
Mori went 4-for-12 with two home runs in four Ni-gun rehab games.