Jurrjens left a Spring Training game on March 24 after one inning due to side discomfort. He has not pitched since, though he did pitch a bullpen session during the series in Washington that he said went well. The bullpen was 30 pitches, mixing in all of his pitches.
However, it seems likely that the Braves will err on the side of caution and place him on the disabled list. The DL date would be retroactive, so he would be eligible to make an April 9 start against the Phillies in Atlanta as the best case scenario. There is no reason to rush Jurrjens back this early and risk added injury when he could make a start just a few days later.
In Jurrjens' place, Mike Minor would likely get the spot start in Milwaukee on April 6.
Jurrjens came into 2011 with higher expectations following an offseason workout regimen, coming in lighter and stronger. He dealt with various injuries throughout 2010, causing the changes. However, his 2011 isn't getting off to a much better start.