Lilley came over from Rochester, which has gone on hiatus. He has coached in the A-League and USL dating back to the Hershey Wildcats, whom he first coached in 1997.
Lilley, Christian Pulisic's godfather, spent six seasons with the Rhinos, winning the USL Cup in 2015. He also coached the Montreal Impact and Vancouver Whitecaps in the A-League and the indoor Detroit Ignition in the MISL. He won Coach of the Year honors with Hershey, Montreal and Detroit.
Pittsburgh, which did not make the playoffs in 2016 and 2017, is tied for third place in the Eastern Conference, four points behind defending champion Louisville City, which is also unbeaten.
The USL's only other unbeaten team after Week 7 is Sacramento Republic FC.