KANSAS CITY, Mo. -- Scott Kingery is zooming towards a minor-league rehab assignment and a return to the Phillies' lineup.

It will be considerably longer before David Robertson is back on the mound.

Kingery went through a pregame workout Friday here at Kauffman Stadium, running the bases, taking grounders on the infield and even fly balls in center field. The super-utilityman, sidelined since April 20 by a strained right hamstring, could resume playing on Monday at low-A Lakewood, according to manager Gabe Kapler, starting the clock on a 20-day assignment that isn't likely to last nearly that long.

Robertson, meanwhile, reached a milestone by playing catch for the first time since going on the injured list on April 15 with a strained flexor in his right elbow/forearm. He lightly tossed from 30 feet away with fellow reliever Tommy Hunter, who is dealing with the same injury.

"It wasn't bad, but not as good as I hoped," Robertson said. "I hoped it would be 100 percent, and it's not there yet."

In other injury news, reliever Victor Arano (elbow inflammation) played catch from 150 feet without a problem. He's scheduled to throw from a mound Tuesday.

Extra bases

Bryce Harper served as the designated hitter in the Phillies’ first game of the season in an American League ballpark. The plan is for J.T. Realmuto to be the DH on Saturday and Andrew McCutchen on Sunday. ... Backup catcher Andrew Knapp will work with pitcher Zach Eflin on Saturday. Eflin has given up two earned runs in his last 16 innings with Knapp behind the plate, but Kapler was strong in saying it won’t become a “personal catcher” situation.