The Nationals’ bullpen has been through its fair share of changes this season, largely due to injuries up and down their pitching staff. Those circumstances have forced the Nats to at times call on rookies to come up and fill in. They have also relied heavily on second-year pros such as Aaron Barrett – who is also now injured – and Blake Treinen.
Lately, though, there has been an infusion of veteran experience with the addition of right-handers Casey Janssen and David Carpenter. Janssen came off the disabled list in late May after recovering from right shoulder tendinitis, while Carpenter joined the Nationals on June 12 after coming over in a trade with the New York Yankees.