PHOENIX -- Tony Gonsolin, set to make his MLB debut as the Wednesday starter, was in the Dodgers' clubhouse Tuesday to get acclimated for his activation. He got the callup news from Oklahoma City manager Travis Barbary.

“My heart started racing, started sweating immediately -- excitement, nervousness, anxious, all the emotions flooded me at once,” said Gonsolin, who has overcome the odds of being a $2,500 signing to make the big leagues in his fourth professional season. “Just need to relax tomorrow and let it happen."

Gonsolin threw nine scoreless innings in Spring Training games for the Dodgers. He was sidelined for five weeks at OKC with a strained oblique, but returned a month ago and has built up to five innings. He considered himself a two-way player at St. Mary’s College and said back then he expected his MLB debut would be as a hitter.

Injury updates

Manager Dave Roberts said shortstop Corey Seager has resumed running and batting as he rehabs from a strained hamstring, but the hamstring injury sustained by first baseman David Freese is healing slower than expected.

Roberts said Seager, outfielder A.J. Pollock and Freese should return after the All-Star break. Originally Freese was expected back before the All-Star break. Scott Alexander (forearm) will face hitters this weekend in games at Camelback Ranch-Glendale.

Lamb a super-scout for Dodgers

The Dodgers drafted and signed 2019 sixth-round pick Aaron Ochsenbein, a right-handed reliever from Eastern Kentucky. Keep an eye on him.

Why? Because he was drafted and signed by scout Marty Lamb, who also drafted and signed Walker Buehler, Caleb Ferguson, Will Smith and Matt Beaty. Lamb’s been discovering Dodgers for awhile, having also drafted Chad Billingsley and A.J. Ellis.

Smith and Beaty joined Alex Verdugo and Kyle Garlick to give the Dodgers four rookies in Tuesday night’s starting lineup against the D-backs.

Lamb provided some insight into why Beaty, who attended Belmont University in Nashville, hit his radar.

“He always had a bat, but the question was where he would play,” said Lamb. “In Instructional League, we tried him at catcher. The analytics guys liked him and when he faced the big schools, like Vandy and Buehler, it didn’t faze him at all and that sort of solidified it in my mind.

“And what showed me about his makeup, Belmont played a night game in a conference tournament and we asked Matt and a teammate, Drew Ferguson, to come to Atlanta for a morning workout. The guys drove all night to be there. It showed a lot about both kids.”

Lamb added this: “Don’t forget [Zach] Reks,” referring to the Oklahoma City outfielder he signed. “He’s crushing the ball.”