PHILADELPHIA -- It's been an uneven first week for the Nationals bullpen, with their young relievers showing off their promise in some instances and frustrating in others.
After Ryan Zimmerman tied Sunday's game with a pinch-hit, three-run homer in the ninth inning, right-hander Koda Glover surrendered the game-winning hit after walking the leadoff hitter on four pitches as the Phillies walked off with the series win and the Nationals lost, 4-3.
Nationals relievers have now given up 17 runs in their first six games, which began the day Sunday as the most in the Majors. They have fallen behind in the count too frequently, and manager Dusty Baker noted the plethora of leadoff walks they have yielded. The runs are a bit inflated by the taxing seven runs and 7 1/3 innings they had to endure after Jeremy Guthrie could not get out of the first inning on Saturday night, but it is not the start the Nationals had hoped for from their young arms.
"You worry about it today, but the life of the reliever is that you have to forget yesterday and work on whatever didn't happen yesterday," Baker said. "You can't take it forward with you. If you can't handle this, how are you going to handle the pressure that starts in the second half and the playoffs and the World Series? So this is a learning process for a lot of them. I've still got confidence in those guys, big-time."
Glover has not been able to shut down hitters with the same success he had in Spring Training and for parts of 2016; he has not struck out a batter this year. Left-hander Sammy Solis walked the leadoff man as well, even though he tossed a scoreless inning Sunday, and he has allowed three runs in three innings this season. Blake Treinen has converted three of his four save opportunities, but opposing hitters are batting .333 off him. Meanwhile, opponents are hitting .500 against left-hander Enny Romero, who has allowed three runs in 2 1/3 innings.
It's only the first week -- still a bit early to panic -- but the Nationals have a few uncertainties in the bullpen.
"It's not a matter of stuff, all those guys down there have what it takes to get people out at this level," Zimmerman said.
"It's about throwing strikes and executing pitches. All of us are going to go through tough times through the season, whether it's a week, two weeks, something like that. You just have to continue doing what you're doing and keep working. I don't have any doubt that those guys [will] be perfectly fine."
• The Nats added a veteran reinforcement to their organization when they reportedly agreed to a Minor League deal with right-hander Joe Nathan, a source confirmed to MLB.com on Sunday. They were impressed with Nathan, 42, out of Spring Training but they did not have room for him on their Major League roster. He was granted his release to look for a big league job, but he had not found any success.
• Baker said shortstop Trea Turner was doing "so-so" a day after he left the game with tightness in his right hamstring. Turner will be re-evaluated on Monday.
Jamal Collier covers the Nationals for MLB.com. Follow him on Twitter at @jamalcollier. This story was not subject to the approval of Major League Baseball or its clubs.