PHOENIX -- Friday saw the return of an injured player, an outstanding pitching performance by Zac Gallen and another loss to the Mets, this one by a 6-5 margin in 10 innings at Chase Field.

Here are three things to know about what transpired for the D-backs in the series opener:

• Box score

1. Gallen was really good (again)
Let's deal with the actual game action first -- Gallen was outstanding, allowing two hits and a run while striking out seven over five innings.

"It was an aggressive fastball," D-backs manager Torey Lovullo said about Gallen's stuff. "It was a down fastball on both corners. The change and the cutter looked like they were working very well, and it looked like he was on a mission."

In two starts this year – both against the Mets – Gallen has allowed just one run over nine innings. Neither of the hits he allowed Friday were struck well. One was a double to left that would have been a routine grounder to third without the shift, and the other was a bloop single to right by Pete Alonso.

"Frustrating is a good way to put it," Gallen said of the hits. "Those are kind of tough. But you know that's the game. Sometimes you get a bad break, sometimes you get a good break. It is what it is."

After battling through injuries last year, a healthy Gallen pitching well is something that bodes well for the D-backs going forward.

2. Ahmed's return means something new for Perdomo
Ahmed had been on the injured list since the start of the season with shoulder inflammation, something that has bothered him off and on since Summer Camp in 2020.

Rookie Geraldo Perdomo, who had gotten most of the starts at shortstop in Ahmed's absence, was on the bench on Friday, but that might not last that long. As one of the club's top prospects, Perdomo's development is a high priority for the D-backs, so having him sit on the bench is not something they want to do.

Rather than send him down to Triple-A Reno, though, it sounds like the plan is to play him at third base, a position that he has never played at the professional level.

"He has not, but he can do it. He'll be just fine," Lovullo said. "He'll get some reps at third. He'll get some reps at second base. I like the infield mixture that we have right now. There are a lot of interchanging parts there, and they all pick up a baseball, they all play at a fast pace."

3. Perform or else
Lovullo waited until Friday to announce that Humberto Castellanos would start Saturday's game against the Mets.

Castellanos' other start of the year came in last Sunday's series-finale against the Mets when he tossed four shutout innings.

Lovullo was asked if Castellanos was going to be a permanent part of the rotation, and his answer was telling.

"No, I wouldn't say that," Lovullo said. "We want to challenge everybody to go out there and continue to be the best version of themselves, and certainly we feel [Castellanos] is ready for this."

Later in the session with reporters, Lovullo was asked about the fact that in the next 10 days the team will need to cut its roster from 28 down to 26.

"It's a different vibe this year," Lovullo said. "You've got to perform or else there's going to be somebody chopping on your heels to take your job. And I think that's just innate -- the players feel that, they sense that, they can see that we've already made several moves and there's good baseball players waiting in the wings. I don't need to say a lot about that. I don't mind competition. Last year, I think we lacked that. The guys were very comfortable here."