His slider, which was "garbage" in his last outing, was "very good today."
"It's really hard to evaluate this," he said of the workout. "You just want to get your pitch count up, work on your routine a little bit, and have a little bit of fun out there, to tell you the truth."
For example, he tried different combinations with his pitches, working with catcher Steve Clevenger.
"The ball the dude hit for a homer, we were working on elevating the ball up in the air, and I elevated it for him, and he hit it out of the park," Samardzija said of Zach Cone's three-run shot. "Certain things like that, you look at it, and the result doesn't necessarily dictate the means.
"Obviously, you want to throw up zeros anytime you're on the mound," he said. "You look at how the pitches went and how everything went and go from there. The way my arm feels, for me that's most important. You have a 10 o'clock game, you want to make sure you get your body warmed up, your arm warmed up."
Cubs manager Dale Sveum was happy with the workout.
"He came out and threw strikes," Sveum said. "It was a controlled atmosphere we wanted to put him in where he got up and down four times. He was working on some stuff you wouldn't do in a regular game. His secondary stuff was good and he was getting strike one, and obviously, getting too much of the plate with his fastballs."
The Rangers had called the Cubs about playing a "B" game, and Samardzija drew the short straw for the long, early drive.
"Situations like that, you can work on one certain aspect, work out of the stretch," he said. "You can kind of control the environment a little more."
Named the Opening Day starter, Samardzija said the good thing is he knows when he'll be pitching -- April 1 against the Pirates.
"I've just been keeping an eye on that date, and making sure all my pitches and windup and stretch and all the little things are right where they need to be for that date," he said. "It just changes things a little with the lead-up to it. You know what the intensity of that game will be. You just take it easy and not let your emotions build up over the next few weeks."