Rangers wanted to see Diekman fatigued. Here’s why:

The goal Saturday afternoon was to absolutely wear out Jake Diekman.

Make him throw a bunch of pitches in live batting practice. Put him through pitchers fielding practice.

Test the strength of his left arm and in general after three operations the first six months of the year to ward off ulcerative colitis.

“My arm feels like it weighs 50 friggin’ pounds,” he said.

Diekman threw 31 pitches to Mike Napoli, Ryan Rua and Drew Robinson at Target Field in what could serve as the final test before being sent on a rehab assignment, preferably Tuesday with Double A Frisco at Little Rock.

The Rangers wouldn’t pinpoint what’s next until after learning how Diekman’s arm and body respond to being put through the wringer. They should know more Sunday morning.

“I’m not going to put a time line on it,” pitching coach Doug Brocail said. “This is his spring training. At some point I need that arm to get tired. I think he’s starting to have that tired phase.”

A reliever typically works eight or nine innings during spring training, including working on back-to-back days toward the end of camp. The Rangers want him to have a dead-arm period now rather than upon his return to the majors.

Once Diekman goes on assignment, he has 30 days to complete it. He might not need all 30 days, but indications are that he hasn’t regained the velocity had before the operations. A radar gun clocked him Saturday, but neither he nor Brocail had been told the velo readings.

Diekman still feels good, though he admitted that the process has been more difficult than he was anticipating. He called his arm strength “terrible,” but he is also itching to get going.

“I feel like I’m ready for a rehab assignment,” Diekman said. “I feel like this is spring training for me. This is terrible. I didn’t know how hard this was going to be ... but I’m hoping to get out of here soon.”

This story was originally published August 5, 2017 at 5:40 PM with the headline "Rangers wanted to see Diekman fatigued. Here’s why:."