CINCINNATI -- Washington Nationals third baseman Nick Senzel was scratched from the Opening Day lineup after breaking a thumb during batting practice Thursday.

Senzel fractured his right thumb on a bad hop and could be out three to four weeks, according to manager Dave Martinez.

"It's awful," Martinez said. "He was in a good spot, and we were in a good spot with him. He was excited. It was just a freak accident. We're going to miss him."

Senzel was signed to a $2 million, one-year contract after playing parts of five seasons with the Reds.

Ildemaro Vargas replaced Senzel in the lineup. The Reds beat the Nationals 8-2.