The New York Mets had a surplus of starting pitchers and middle infielders heading into spring training. Now they're looking thin in both of those departments, with the latest injuries occurring to their second baseman and shortstop.

Last Thursday starting second baseman Daniel Murphy left the team's spring training game in the first inning because of tightness in his right hamstring. The veteran received an MRI, but the Mets only disclosed that Murphy would be shut down for at least the next week because of a pulled hamstring. At this point it appears he could start the season on the disabled list.

On Sunday, shortstop Wilmer Flores fouled a ball off his left foot and remained in the game, but left the field in a walking boot. He underwent X-rays, which came back negative, and was diagnosed with a bruised left foot and will remain in the boot for at least another day, according to Mike Puma of the New York Post.

"He was limping around pretty good," manager Terry Collins told Puma. "If you watched him [run] down to first base you could tell it was bothering him, so he is going to be pretty sore [Monday]."

Flores told Marly Rivera of ESPN Deportes that he was "in a lot of pain."

Being that the injury timetables for Murphy and Flores are unclear, who will the Mets start in their middle infield if these two were to start the year off on the disabled list?

"Matt Reynolds and Danny Muno are auditioning to fill in for Murphy if he requires a season-opening DL stint," writes Adam Rubin of ESPNNewYork.com.

"Ruben Tejada, plus Reynolds and Muno, would be the logical candidates to start at shortstop if Flores were forced to miss the beginning of the season."

Many believed prospect Dilson Herrera was the heir-apparent for Murphy, who is slated to hit free agency after the season, but a team source explained to Rubin why that's not the immediate case:

"Mets officials, on a strict performance basis, preferred to call up Reynolds or Muno from Triple-A Las Vegas when the need for an infielder arose in late August of last season. Instead, the team called up Herrera directly from Double-A Binghamton and bypassed Reynolds and Muno at the time because Herrera needed to be added to the 40-man roster during the offseason anyway to protect him in the Rule 5 draft."

Herrera also had a poor spring training (.059/.158/.059 with two runs scored, one hit and two RBIs in eight games) and instead will continue to get time in the minors.

Here are the stats for the leading candidates to fill in for Murphy and Flores:

Ruben Tejada - .237/.342/.310 with 30 runs scored, 5 home runs and 34 RBIs in 119 games with New York in 2014.

Matt Reynolds - .343/.405/.454 with 87 runs scored, 6 home runs, 61 RBIs and 20 stolen bases in 126 games with Double-A Binghamton and Triple-A Las Vegas in 2014.

Danny Muno - .259/.372/.418 with 74 runs scored, 14 home runs, 62 RBIs and 9 stolen bases in 117 games with Triple-A Las Vegas in 2014.

We'll see how the competition goes throughout the remainder of spring training.