BOSTON One great story was balanced out by a not-so-encouraging one as the Milwaukee Brewers opened a series at Fenway Park on April 6.Called up from Class AAA, potentially to face the team that traded him this off-season, was Shane Drohan, but the left-hander was taking the spot of a fellow southpaw who was on the receiving end of some discouraging news.Reliever Jared Koenig was placed on the 15-day injured list with a left elbow sprain, an injury manager Pat Murphy called a big concern.Koenig is going to try to rehab the injury and avoid surgery, Murphy added, with the hope being he returns in two to four weeks.Bad news for us, but were going to try and rehab it, Murphy said.Koenig was an unsung hero for the Brewers the past two years by Murphys book, pitching in any role and performing well while doing so. He had a 2.67 ERA over 127 games and 128 innings in his first two seasons with the Brewers, but came to spring training throwing noticeably softer than his standard upper-90s velocity. That carried over into the regular season, and his sinker averaged 93.5 mph in his outing April 4 in Kansas City.He did feel it last outing more than ever, Murphy said. He had a little forearm tightness early in spring. We were a little tentative on how we used him. We were aware, at least, that he wasnt his normal self.Shane Drohan to make his MLB debutDrohan may make his big-league debut at Fenway this week, but it isnt his first time at the revered old ballpark.He pitched there in a game against Boston College while at Florida State, then was back for a Red Sox rookie development camp in January. A month later, of course, Drohan was sent to Milwaukee as part of the three-player return for Caleb Durbin. The other two players, David Hamilton and Kyle Harrison, were both on the Brewers roster for the series, as well.The 27-year-old downplayed any significance of his debut potentially coming against the team that drafted him in the fifth round in 2020.Not really. Its just pitching in the big leagues that has always been the goal, he said. I was never really worried about what uniform I was wearing. I just wanted the ball in the big leagues and thats what it will be.That moment could come at any point in the series for Drohan, but is most likely to land April 8. The Brewers do not have a starter listed for the series finale, which would line Drohan up to make that start, but he will also be available in long relief the first two games against Boston.This article originally appeared on Milwaukee Journal Sentinel: Milwaukee Brewers reliever Jared Koenig goes on injured list