Fister tries to win a fourth consecutive start as the Nationals go for a three-game home sweep over the slumping Philadelphia Phillies on Thursday.
Acquired from Detroit in December, Fister (3-1, 3.34 ERA) missed all of April with a lat strain before getting tagged for seven runs - five earned - over 4 1-3 innings in an 8-0 loss at Oakland in his season debut May 9. However, the right-hander has since gone 3-0 with a 2.13 ERA in his last four outings while striking out 21 and walking two over 25 1-3 innings.
He yielded two runs and four hits over six innings in Saturday's 10-2 victory over Texas.
"He's got the ability to work quickly, which certainly helps your defense," manager Matt Williams said. "They expect the ball to be put in play."
Although he hasn't needed much help, Fister is receiving an average of 11.3 runs of support in his last three outings.
"Run support in general is always an important stat," Fister told MLB's official website. "It's something that's not only a number thing, it's a morale booster, it's a momentum builder, it's everything that a team wants to do, and it's kind of the equivalent to a pitcher going out there and putting up zeros."
In his only appearance against the Phillies, Fister surrendered one unearned run and three hits over eight innings in a 2-1 win with the Tigers on July 26.
The Nationals (29-28) have won four of five by a 34-10 margin after beating Philadelphia 8-4 on Wednesday. Stephen Strasburg threw seven strong innings and Anthony Rendon went 3 for 5 with a homer and three RBIs.
"It's been a lot of fun for us, pitching the ball good and swinging the bat well," said leadoff hitter Denard Span, who is batting .448 with three doubles and seven RBIs during a six-game hitting streak. "Hopefully we keep it going."
The Phillies (24-33) have been outscored 35-13 while going 7 for 42 (.167) with runners in scoring position during a season-worst five-game losing streak. They went 1 for 10 in such situations Wednesday, dropping to 2-10 in their last 12 in Washington.
"Sun is going to come up, believe it or not," said losing pitcher A.J. Burnett, whose team is an NL-worst 9-19 since May 5. "It might be a little cloudy."
Philadelphia now turns to Kyle Kendrick (1-5, 4.21), who is 1-10 with a 4.84 ERA in his last 18 starts dating to August. That lone victory came behind 6 2-3 innings of six-hit ball in a 9-0 victory over Colorado on May 26, but Kendrick's scuffles resumed in Saturday's 5-4, 14-inning loss to the New York Mets.
The right-hander allowed four runs, eight hits and two walks over six innings. Unlike Fister, he's been backed by a combined 10 runs of support in six starts since the beginning of last month.
Kendrick is looking to snap a 10-start winless funk on the road, a stretch during which he's gone 0-7 with a 5.49 ERA. He compiled a 9.88 ERA in losing each of his three starts in the nation's capital last year.
Ian Desmond and Ryan Zimmerman are a combined 30 for 81 (.370) with four homers against Kendrick. However, Adam LaRoche is 5 for 32 in their matchups, and Danny Espinosa is 3 for 19.