Nationals placed RHP Matt Waldron on the 15-day injured list, retroactive to September 5, with chest inflammation.

Waldron hits the shelf following three appearances for the Nationals after being claimed off waivers from the Blue Jays last month. The 29-year-old holds a lackluster 6.54 ERA across 42 2/3 innings between the Nationals, Blue Jays and Padres this season.