Keuchel, who won the Cy Young Award in 2015, has a 1.84 ERA, 54 strikeouts and has held opposing hitters to a .186 batting average in his nine starts this season. This is his first trip to the DL in his major league career.
"We hope that this can knock out any sort of lingering soreness," manager A.J. Hinch said Saturday. "I'm not a doctor. I don't know what has to happen between now and then other than the diagnosis is a pinched nerve and we need to calm it down a little bit before he can resume his activity."
The left-hander has the lowest ERA in the majors and his wins are the most in the AL and tied for most overall.
The Astros expect Keuchel to miss only one start, and the DL move is retroactive to Wednesday.
"Given the day off that we had and the nine games that he's going to miss, there's a chance that he could be right in rotation as we would have expected him to be,'' Hinch said. "But I won't know until he does a little bit more activity.''
Right-hander Brad Peacock (2-0, 1.10 ERA) will move out of the bullpen to start Monday. He has bounced between starting and the bullpen in his career and started five games for Houston last season and 46 in his six-year major league career.
Keuchel pitched just five innings in his last start -- a 12-2 win over the Marlins on Tuesday -- allowed two runs on four hits while striking out four.
Hinch was pleased that Keuchel came to them as soon as he noticed the problem. In the past he has sometimes tried to pitch through problems instead of taking a step back.
"This is not easy for Dallas because No. 1 he loves making all of his starts and No. 2 he feels like he's Superman, he can do anything and pitch through anything ... so (I'm) very happy that he's honest with us with how he felt,'' Hinch said.
"Obviously we don't want him to miss a start. He's going to miss a start, but better than this lingering for a longer period of time."
The Astros recalled left-hander Ashur Tolliver from Triple-A Fresno to take Keuchel's spot on the roster. Tolliver has a 2.70 ERA in 10 relief appearances for the Grizzlies this season.
The Associated Press contributed to this report.