The Rangers also said Holland will not throw for a week as he continues to try and add weight and strength. He will be evaluated further next Friday.
Holland was placed on the 15-day disabled list Thursday with shoulder fatigue. He said he has also lost 15 pounds in the last 2½ weeks because of the stomach ailment.
"The club is very relieved by Dr. (Keith) Meister's findings, allowing us to turn our focus on helping Derek regain his strength and weight," Rangers assistant general manager Thad Levine said in an email.
Before the MRI, Rangers manager Ron Washington said he wasn't sure if Holland's weakness was a result of the virus.
Holland joined fellow starter Neftali Feliz, who has a sprained ligament in his throwing elbow, on the disabled list. Feliz could be out until after the All-Star break.
The Rangers last week signed veteran right-hander Roy Oswalt, who is building up innings in Round Rock. He was tagged with a loss in his second Triple-A start Thursday against Omaha, allowing five runs on six hits -- including a grand slam -- and a walk to go with four strikeouts in four innings.