Short-handed Galaxy adds goalkeeper Trey Mitchell

Trey Mitchell must have figured he was running out of chances.

Since leaving Cal State Dominguez Hills after the 2013 season, Mitchell has played for the Chivas USA reserves, was called into preseason training camp with Real Salt Lake and had a four-week trial with Louisville City of the third-tier USL Pro league.

All those paths led to dead ends. So when the Galaxy, Major League Soccer’s defending champion, called with another offer last week, it sounded like a cruel joke.

But after Mitchell had one training session with goalkeeper coach Matt Reis and another with the full team, the Galaxy offered Mitchell both a contract and a seat on the plane for Saturday’s game with D.C. United.

“I really haven’t had time for it to sink in yet. It’s all happened pretty quickly,” Mitchell, 23, said Friday by phone from Washington.

The Galaxy couldn’t afford to be too picky. With starting goalkeeper Jaime Penedo away on international duty with Panama and third-choice keeper Brian Perk lost for the season after ankle surgery Friday, the team needed a backup for Brian Rowe, who will start in goal Saturday.

“I was definitely keeping my head up … and working hard for any call that I got,” said Mitchell, who allowed less than a goal a game in two seasons at Dominguez Hills, making him the fourth-best keeper in school history.

“Trey’s always committed himself to trying to get better so that he could get to that level,” said Dominguez Hills Coach Joe Flanagan, who added that he’s sent about a half-dozen players on to MLS.

The Galaxy also will play without forward Robbie Keane, who is on international duty with Ireland’s national team, and strike partner Gyasi Zardes, who is with the U.S. squad. Keane has two of the Galaxy’s five goals this season; Zardes has one.

In their absence, Galaxy Coach Bruce Arena probably will give veterans Edson Buddle and Alan Gordon their first starts of the season.

GALAXY AT D.C. UNITED

When: 4 p.m. PDT Saturday.

Where: RFK Memorial Stadium, Washington, D.C.

On the air: TV: TWC, TWC Deportes; Radio: 1330, 980.

Records: Galaxy 1-0-2, D.C. United 1-1-0.

Record vs. D.C. United (in 2014): 1-0-0

Update: The Galaxy is unbeaten three games into the new season but hasn’t looked good getting there, playing especially poorly in last week’s home draw with the Houston Dynamo. Without four of its best players — forwards Robbie Keane and Gyasi Zardes, midfielder Bradford Jamieson IV and goalkeeper Jaime Penedo, who are all away on international duty — the Galaxy meets defending Eastern Conference champion D.C. United on the road. Keane (two) and Zardes (one) have combined for three of the Galaxy’s five goals this season. United, meanwhile, will be without suspended forward Fabian Espindola. The Galaxy hasn’t lost to United since 2008, a streak of 10 games.

kevin.baxter@latimes.com