Jackson and Martinez on injury report (updated)

SARASOTA, Fla. - First baseman Conor Jackson came off the field early today after his lower back tightened while fielding ground balls during the workout. "It was just a little back issue. Nothing crazy," said Jackson, 30, who signed a minor league deal Dec. 5. "With three days left before games start, just want to be careful about it. Kind of what the trainers preach from day one. If you've got something, you don't want to let it linger. I don't think it will linger. "I hadn't taken ground balls in a while, so it was kind of a new body movement for me, I guess. I don't think it's going to be a stupid-long period of time. "I don't think it's anything crazy. Just want to be careful with it. The worst thing you can do is let something like this linger." Jackson, who also plays the outfield, said he plans on being ready for Saturday's exhibition opener against the Minnesota Twins in Sarasota. Catcher Luis Martinez joined Jackson in the trainer's room after straining his left oblique while taking batting practice. He's hoping to play in one of Wednesday's intrasquad games. "Pretty minimal. I just want to take care of it before it got any worse, especially in that area, where it can be very sensitive," said Martinez, who was claimed off waivers last month, designated for assignment and outrighted to Triple-A Norfolk. "This is the first time. I just wanted to make sure it was OK. Take care of it. Ice it, stem it and be ready to go tomorrow." Right fielder Nick Markakis will leave camp after Wednesday's intrasquad games to attend a funeral in Baltimore. He will be away from the team for a few days. "He thinks he should be there and that's good enough for me," said manager Buck Showalter. Manny Machado was cleared to work out today, but the Orioles are waiting for the results of the tests administered yesterday related to acid reflux symptoms. They want to make sure the condition isn't being caused by an ulcer. Same thing with non-roster pitcher Zach Braddock, who's been limited in camp after undergoing labrum surgery last year. Reliever Luis Ayala was sick yesterday, but he threw a bullpen session today. The Orioles will play two three-inning intrasquad games Wednesday beginning at 10:15 a.m. on two of the back fields, which means Showalter will be posting four lineups. The Orioles also will play a six-inning intrasquad game on Thursday. I'll be updating this entry later with the pitching schedule for Wednesday and, hopefully, the starter for Saturday's exhibition opener. Update: Steve Johnson, Zach Clark and Mike Wright will oppose Todd Redmond, Dylan Bundy and T.J. McFarland Wednesday on field No. 3, and Tommy Hunter, Zach Britton and Adam Russell will oppose Jake Arrieta, Brian Matusz and Jair Jurrjens on field No. 4. On Thursday, left-handers Mark Hendrickson, Troy Patton, Daniel Schlereth and Eduardo Rodriguez will oppose Chris Tillman, Pedro Strop, Daniel McCutchen, Mike Belfiore and Kevin Gausman. Thursday's game will begin at 1:05 p.m. on the main field. No word yet whether it's open to the public.