WASHINGTON -- Yonder Alonso hopes he can make his new opportunity a bright one for himself and the Rockies.

Alonso rejoins manager Bud Black, his skipper in San Diego from 2012-15, with hopes of providing left-handed production and power. The 32-year-old struggled in limited playing time with the White Sox, putting up a slash line of .178/.275/.301 before being released July 3. After signing with the Rockies during the All-Star break, Alonso went 13-for-31 (.419) with two home runs and 12 RBIs at Triple-A Albuquerque.

The left-handed-hitting Alonso, an All-Star in 2017, essentially replaces righty first baseman Mark Reynolds, whom the Rockies designated for assignment on Sunday. To clear room on the 40-man Major League and 25-man active rosters, the Rockies designated righty Seunghwan Oh (set for season-ending right elbow surgery) for assignment, and optioned righty reliever Yency Almonte to Albuquerque.

When a player's contract is designated for assignment -- often abbreviated "DFA" -- that player is immediately removed from his club's 40-man roster, and 25-man roster if he was on that as well. Within seven days of the transaction (it was previously 10 days), the player must either be traded, released or placed on irrevocable outright waivers.

Almonte, however, will likely return to the club Wednesday as the extra player allotted for a doubleheader against the Nationals.

Last season, Alonso batted .250 with 23 homers and 83 RBIs for the Indians, who traded him to the White Sox during the offseason. The time in Albuquerque allowed Alonso to re-accustom himself to regular playing time.

“I was putting together some really good, grinding at-bats, and when I was hitting the ball, hitting the ball solid to all fields,” Alonso said. “I was able to face some lefties, face some righties, some closers and pretty good starting pitchers."

Black will have to balance out some aspects of playing time, with regular first baseman Daniel Murphy also batting left-handed. But there should be plenty of pinch-hit or substitute opportunities, before and after rosters expand Sept. 1. In addition, Alonso's presence could be a factor with the July 31 Trade Deadline approaching.

He drove in the Rockies' only run in Tuesday night's 11-1 loss to the Nationals in Washington, an RBI double in the ninth inning.

Black noted that Alonso has been a solid fielder at first base -- a factor that can increase his usage with the Rockies.

“When we signed him," Black said, "the hope was he could bounce back a little bit from the rough go that he had this season and see if there’s something that [in] the next couple months he can help win games, with his style of play.”

Alonso referred to Black as “a winner.” He also has looked back to his time with the Indians last year for inspiration for his new role with the Rockies.

“It happened in Cleveland for me last year,” Alonso said. “Josh Donaldson came in around this time. We were struggling, and he was able to do some really big things for us during that time. I take some notes from that, and hopefully I can bring those things here.”

New plan with Rusin

The Rockies designated lefty pitcher Chris Rusin for assignment on June 7, when he could not find his form after a mid-back strain that dated back to Spring Training. But Rusin could return in a new role.

Rusin, 32, cleared waivers and accepted assignment to Albuquerque. His last two appearances have been starts, during which he has held opponents to one run on 10 hits in eight innings while building his pitch count. With multiple young starters struggling, there are possibilities for Rusin to return.

“We’re looking for depth, anywhere we can find it, and he’s done it before,” Rockies pitching coach Steve Foster said. “Let’s give it a shot. It’s been discussed throughout the year, but it became a reality recently. There’s some promise.”

Pitching plans after rainout

Black said righty Jon Gray (9-7, 4.11) is scheduled to start the first game and lefty Kyle Freeland (2-7, 7.62) the second in Wednesday’s doubleheader against the Nationals. Barring some unforeseen pitching struggles that tax the bullpen in those two games, righty Jeff Hoffman (1-3, 6.75) is lined up for the series finale Thursday afternoon.