 On 5 June 2015, Grella scored his third goal of the season in a 4–2 loss versus the Houston Dynamo.On 24 June 2015, Grella scored New York's lone goal in a 1–0 victory over Real Salt Lake.On 1 July 2015, Grella scored his fifth goal of the season for New York, helping the Red Bulls to a 4–1 victory in the U.S. Open Cup over local rival New York Cosmos.