Matz (forearm) will not come off DL when eligible

Oswalt to fill in for left-hander on Saturday vs. Marlins

August 7th, 2018
New York Mets starting pitcher Steven Matz throws during the first inning of the team's baseball game against the Washington Nationals at Nationals Park, Tuesday, July 31, 2018, in Washington. (AP Photo/Alex Brandon)Alex Brandon/AP

NEW YORK -- , who hoped to skip only one start after sustaining a flexor-pronator strain in his left forearm, will instead miss multiple. The Mets have scheduled to make another start Saturday against the Marlins, ensuring that Matz will not come off the disabled list when eligible.

While Mets manager Mickey Callaway said that Matz "is going to progress and keep on progressing," he could not reveal when Matz might pitch again. The left-hander, who is 5-9 with a 4.35 ERA in 21 starts, threw a 15-pitch bullpen session on Monday.

Matz's extended absence creates more opportunity for Oswalt, who is 1-1 with a 3.81 ERA over his last five outings.

Flexen undergoes procedure

One starting pitcher who will not be an option down the stretch for the Mets is , who underwent surgery this week to repair a torn meniscus in his knee. Flexen, who posted a 12.79 ERA in one start and three relief appearances for the Mets, has been on Triple-A Las Vegas' disabled list since Friday.

In 17 starts and one relief outing for the 51s, Flexen produced a 4.40 ERA.

Stalled progress

The Mets continued to have little to report Tuesday regarding outfielder , who has been on the DL since June 19 due to a right hip strain. Bruce, who has also spent much of this season battling foot and lower-back ailments, is "in a good spot," according to Callaway, but not close to beginning a Minor League rehab assignment.

In the first season of a three-year, $39 million contract, Bruce is batting .212 with three home runs and a .613 OPS.

"We've just got to accelerate that program enough to get him in rehab games," Callaway said.

Closer by committee

Each of the Mets' three most recent save opportunities has gone to different players: , who is on the disabled list; , who has served as the team's primary closer for much of the last three weeks; and , who recorded his first save in Monday's win over the Reds.

Expect that trend to continue as the Mets look to try out some of their younger relievers in high-leverage spots, while scaling back the workloads of Gsellman and . Callaway mentioned rookies and as two pitchers he would like to try out in pressure spots down the stretch.

"You always want to try to take into consideration who the pitchers are, what they care about, what the team needs and how to win a game," Callaway said, a day after inserting Wahl into a bases-loaded, one-out situation with Joey Votto at the plate. "When you don't have that guy that is the actual closer, or identifies himself as the closer, it does make it easier."

Key to the Mets' end-game machinations will be Gsellman and Lugo. While Callaway wouldn't get into specifics about how he plans to limit the two young pitchers, he and pitching coach Dave Eiland have authored a set of guidelines to ensure that neither is overused at the tail end of a lost season. Gsellman entered Tuesday's play ranked second in the National League with 62 2/3 relief innings, while Lugo had 78 1/3 as both a starter and reliever.

Callaway also mentioned that Lugo could start games in September.