PHOENIX -- D-backs utility infielder Tony Abreu was slated to make his first start of the young season Saturday against the Pittsburgh Pirates at Chase Field, filling in for Stephen Drew at shortstop and inheriting Drew's No. 2 lineup slot.

Abreu played an inning of defense and singled off reliever Hayden Penn in Arizona's Friday night 9-1 win over the Pirates.

"I don't get to play every day, so getting [a start] today is good," Abreu said, adding he hasn't been given any playing-time assurances.

Manager A.J. Hinch said he has made a concerted effort to offer early opportunities to Abreu, outfielder Gerardo Parra and catcher Chris Snyder, three key members of the squad's bench.

"It's hard to get those guys starts because I don't want to take our starters out very often," Hinch said.

Parra and Snyder both started and snared a base hit last Wednesday against the San Diego Padres; Abreu is the last of the trio to get his turn.

Abreu, who backs up Drew at short and Kelly Johnson at second base, batted .345 in his first Spring Training as a member of the D-backs.

"Early going, I'm forcing him in there because [there are] so many off days," Hinch said. "I want to keep him sharp because he swung the bat so well during Spring Training.

"He can play every day if we needed him to."

Webb to play catch Monday

PHOENIX -- Injured starting pitcher Brandon Webb will play catch on Monday, D-backs manager A.J. Hinch announced hours before his team's game Saturday evening opposing the Pittsburgh Pirates.

"I've come with breaking news today," Hinch said in jest to reporters, responding to the daily, "obligatory Brandon Webb question."

Webb, who hasn't thrown since receiving a cortisone injection on March 31, has been restricted to his strength and conditioning regimen. He underwent surgery on his right (throwing) shoulder in August and last threw a bullpen session in early March.

"It's a step forward," Hinch said of his ace playing catch early next week. "Now, we all want it to go faster, but as we've seen with Chris Young in San Diego and [Jeff] Francis in Colorado, it's a tedious process to get back to hundred percent."

Montero to have MRI on knee

PHOENIX -- Catcher Miguel Montero suffered an injury to his right knee early in the D-backs' game Saturday evening against the Pirates at Chase Field.

Following the D-backs' 6-3 loss, manager A.J. Hinch said Montero had left the ballpark for an MRI. Montero wasn't in pain and didn't have much swelling on the knee, Hinch said.

"Anytime you talk about knees, it's scary," added Hinch. "We'll hope for the best during the test and then react accordingly."

In the bottom half of Saturday's second inning, Montero hit a grounder to Pirates starting pitcher Zach Duke. After Duke tagged him out in front of first base, Montero bent down and attempted to extend the knee. First-base coach Matt Williams and Hinch helped Montero off of the field.

Backup catcher Chris Snyder was inserted into the game in the top of the third. Snyder assumed Montero's sixth spot in Arizona's lineup.

"It cringes your heart anytime you see a player like that go down," said teammate Conor Jackson. "I hope that MRI is clean."

The D-backs won't know the severity of the injury until test results become available. Hinch noted he had planned to start Snyder Sunday in the D-backs' series finale with the Pirates.

Montero had started the season on a hot streak despite a subpar Spring Training. In fact, he batted just .180 (9-for-50) at the plate during his team's tuneup in Tucson.

"I wasn't really looking for a hot spring; I would rather save it for the season," Montero said, smiling.

Simply put, he had. Montero, who starts ahead of Snyder behind the plate, was 6-for-11 with three RBIs in three games prior to Saturday.

Montero added he's attempting a carry over not from the spring, but from the 2009 season, during which he established careers highs in batting average (.294), doubles (30), home runs (16) and RBIs (59).

D-backs undecided on fifth starter

PHOENIX -- The D-backs won't need a fifth starting pitcher until their April 17 matchup against the San Diego Padres. But the battle for that assignment is ongoing.

Prior to hosting the Pirates at Chase Field Saturday evening, manager A.J. Hinch said the likely choice for that post will be among three right-handers -- Kevin Mulvey, Billy Buckner and veteran Kris Benson.

Mulvey pitched the Reno Aces' (Triple-A) opener against the Fresno Grizzlies on Thursday, allowing two earned runs on six hits over 6 1/3 frames. He struck out four and walked one.

Hinch said Buckner was scheduled to start Sunday, Benson on Monday, meaning each of the trio would have at least one Minor League start under his belt before the D-backs decide how to round out their Major League rotation.

"We'll see how the competition goes in their Triple-A outings," Hinch hedged.

Hinch added the team won't make a roster move until late next week. The D-backs are currently carrying eight relievers; teams traditionally carry seven.