PHOENIX -- The A's on Friday agreed to terms with 13 of their selections from the 2012 First-Year Player Draft, including fourth-round selection B.J. Boyd.

Boyd, a center fielder out of Palo Alto (Calif.) High School, hit .507 with 25 stolen bases in 28 games and also drew 19 walks for a .628 on-base percentage.

Five other players picked in the first 20 rounds signed contracts with the A's, including right-handed pitcher Cody Kurz (7th round, Oxnard JC), center fielder Brett Vertigan (10th, UC Santa Barbara), right-handed pitcher Stuart Pudenz (13th, Dallas Baptist), right-handed pitcher Austin House (14th, New Mexico) and right-handed pitcher Vincent Voiro (15th, University of Pennsylvania).

Oakland also agreed to terms with right-handed pitcher Tyler Hollstegge (21st, UNC-Greensboro), right-handed pitcher Tucker Healy (23rd, Ithaca), right-handed pitcher Kayvon Bahramzadeh (24th, Kansas State), right-handed pitcher Derek Hansen (25th, Augustana), catcher Phil Pohl (28th, Clemson), left-handed pitcher Taylor Massey (29th, Dallas Baptist) and catcher Ryan Gorton (31st, Oregon State).

The deadline for signing drafted players is July 13. The A's are hopeful they'll be able to reach a deal with first-round pick Addison Russell, a shortstop out of Florida's Pace High School who has a scholarship offer to Auburn.

Injured Cespedes may pinch-hit this weekend

PHOENIX -- Though injured A's outfielder Yoenis Cespedes isn't likely to return to the starting lineup until next week in Denver, manager Bob Melvin is hopeful his cleanup batter may be a pinch-hit option during this weekend's three-game Interleague series against the D-backs.

Cespedes, who strained his left hamstring in Thursday's 7-1 win over the Rangers, took part in limited hitting activities inside on Friday and is expected to join the team on the field for batting practice on Saturday. If all goes well, he could potentially come off the bench in the later innings.

"He looked like he was fairly comfortable walking, so I think we'll know more tomorrow when we get him on the field and get him swinging a bat," Melvin said.

Both Melvin and Cespedes are still hopeful a disabled-list stint won't be necessary, which is welcome news, considering the outfielder was already absent for three weeks with a strained muscle in his left hand. Since his June 1 return, he's boosted a sluggish A's offense, hitting .400 with three doubles, one triple and a home run. He has six hits in his past six plate appearances.

"You look at how well we do offensively when he's in the lineup, compared to when he's not, it's pretty significant," Melvin said. "He takes a lot of pressure off other guys in the middle of the order. He's a true No. 4 hitter for us, and just a terrific athlete."

Cahill, Parker ready for fateful matchup

Courtesy of D-backs associate reporter Tyler Emerick

PHOENIX -- As the centerpieces of the offseason trade between the D-backs and the Athletics, all eyes will be on Trevor Cahill and Jarrod Parker when they meet Saturday at Chase Field.

"It's cool how it worked out," Parker said. "This is what everyone wants to see, right?"

Even though onlookers will view the game as a way to help determine who got the better end of the deal, the people around the matchup are attempting to downplay the magnitude of one start.

"It's pretty much the same," Cahill said. "Just trying to pitch normal and not think about it too much."

"I think everyone looks forward to it, but we probably don't get caught up in it as much as the fans who have maybe rooted for both," Athletics manager Bob Melvin said. "But there's definitely some intrigue to it."

After struggling in Spring Training against the D-backs, walking seven batters in 3 2/3 innings, Parker rolls into the anticipated matchup coming off the best performance of his young career in his last start. The righty had a no-hitter through seven innings and ended up holding the Rangers to one hit over eight innings.

"I feel a lot more comfortable now than I did then. It was Spring Training, and this time it counts," Parker said. "I feel like I know myself a little better, and I know the guys around me better. Kurt [Suzuki, catcher] and I have developed a good relationship, and I trust everything he says."

Cahill also is pitching well, he tossed a shutout against the Padres in his last start.

The 24-year-old who spent three seasons with Oakland is excited to see old friends more than anything.

"I went to dinner last night with [Brandon McCarthy]," he said. "My fiance is hanging out with some other Oakland families. I'm sure I'll see them around, too."

Worth noting

• Melvin got a ride to Chase Field on Friday from opposing manager Kirk Gibson, who was on Melvin's staff when the current A's skipper was managing in Arizona.

"I needed a ride," Melvin said, smiling, "and I was on his way."