With Ketel Marte on the injured list, the D-backs looked to improve their depth in center field by acquiring outfielder Nick Heath from the Royals on Saturday in exchange for Minor League right-hander Eduardo Herrera.

Heath still has to pass through COVID-19 protocols before he's eligible to join the big league roster. That was not expected to happen in time for Saturday afternoon's game with the Nationals.

Heath, 27, opened the 2021 season at the Royals' alternate training site and was designated for assignment April 14. He made his Major League debut last year with the Royals and was 2-for-13 in 15 games.

Since Marte went down April 7 with a strained right hamstring, Tim Locastro had played every inning of every game until he left Saturday's game with an injury. The alternative is Pavin Smith, who had never played center in a regular-season Major or Minor League game until he moved out there from first base Saturday to replace Locastro.

Marte has made progress since his injury, D-backs manager Torey Lovullo said. He took some swings off the tee Friday and did some light running.

"He's feeling good, which is very encouraging," Lovullo said. "He wants to do more, which we want to hear, but we've got to make sure that before we do more, though, that he's in a very, very good spot."

Soria progressing
Reliever Joakim Soria, who suffered a strained left calf April 4 against the Padres, threw a 20-pitch bullpen session Friday and came through it without any discomfort.

Because Soria has been able to keep playing catch since the injury, and because as a closer he will typically pitch only one inning, it should not be long before he is able to return to the active roster.