Musgrove (3-3, 3.79 ERA), acquired from Houston in the offseason, is expected to come off the disabled list to make just his eighth start of the season Tuesday against the Washington Nationals at PNC Park.
This is his second trip to the DL. He began the season out of action because of a shoulder injury. More recently, he went on the shelf because of a right index finger infection. Tuesday is the first day he is eligible to be activated.
Whether it has been the injuries or adjusting to the National League or something else, Musgrove, 25, has been inconsistent when he has been available to the Pirates.
He won his first two starts with strong performances -- giving up one run in seven innings against the Chicago Cubs and throwing seven shutout innings against St. Louis. He went 1-3 in his next five starts.
On June 29, Musgrove had another seven-inning shutout performance in a win in his hometown of San Diego with family and friends watching. Then came the infection.
"It sucks. It's such a stupid injury," Musgrove said. "I don't know what I could have done, really, to prevent it. It's frustrating to be back on the DL again ... especially coming off the (start) I just had. I felt like it was something I could build on."
The Pirates (42-48) could use the top-of-his-game Musgrove as they try to get back above .500 and salvage their season. They won the series opener 6-3 on Monday over the Nationals for their second straight win, but have lost six of their past nine games.
Washington (45-45) has lost two in a row and seven of 10.
Musgrove, who threw a scoreless inning against Washington last season while with Houston in his only career appearance against the Nationals, will oppose right-hander Jeremy Hellickson (2-1, 3.81).
Hellickson got a huge lift from his teammates his last time out in a game that could prove pivotal.
After Washington was swept by Boston and had a five-game losing streak, the Nationals held a players-only meeting July 4.
"Let's get this thing going," Trea Turner said of the gist of the meeting. "I think we all know that we are capable of playing better baseball, and it's time we do it. It's do or die now."
The next day, Hellickson started against Miami, his second appearance since coming off the DL and coming after he had been dealing with an illness for at least several days. He got rocked. He allowed nine runs (eight earned) and nine hits in four innings.
But something unusual happened. Washington rallied from a nine-run deficit to win 14-12, kicking off a three-game winning streak.
The Nationals aren't flourishing but aren't in quite the dire straits this time for Hellickson, who has a 1.59 ERA in two career starts at PNC Park.