NEW YORK (AP) — Mets outfielder Dominic Smith was placed on the 10-day injured list Saturday with a stress reaction in his left foot.Smith wore a walking boot in New York's clubhouse and is scheduled for a CT scan Monday. He is batting .278 with 10 homers, 22 RBIs and an .858 OPS in 88 games this season, his third in the majors. It's unclear how long he will be out."That's a tough one. You hate to lose him. He obviously has been having a great year," Mets manager Mickey Callaway said. "You wouldn't even be able to tell anything by the way he was running."The 24-year-old Smith said he first began feeling discomfort about a week ago, but didn't mention it to the training staff until Friday night. He was sent Saturday morning for an MRI that showed the stress reaction."You feel something and you don't think much of it. We're all competitors here and we all play through those things. I was just playing through it and didn't think much of it," Smith said. "It just was getting worse."He was surprised to learn he had a stress reaction."It's definitely a bummer," Smith acknowledged. "I didn't think it was this severe. I woke up this morning, I felt really good. My foot felt really good since the last couple days. I was excited about today. Then to get in and hear the news, it just hurt. It hurt a lot. I'm very disappointed, very sad. I'm just going to do everything I can to get back out there as soon as I can."A natural first baseman, Smith has been starting in left field against right-handers to get his bat in the lineup despite his defensive shortcomings in the outfield. He is blocked at first base by rookie slugger Pete Alonso.Right-handed hitter J.D. Davis was in left field Saturday night against Pittsburgh Pirates righty Trevor Williams. The fourth-place Mets selected the contract of outfielder Aaron Altherr from Triple-A Syracuse, and he was available on the bench.Altherr was 1 for 10 with a home run and six strikeouts for New York earlier this season. He was hitting .274 with four homers and eight RBIs in 23 games at Syracuse.Smith was drafted 11th overall by the Mets in 2013. He sputtered during his initial big league chances the last two years, but has shown marked improvement at the plate this season — including when summoned as a pinch hitter."Once the further tests come out, then we'll figure out where to go from there," Smith said. "Very sad day for me. Just very upset this happened."___More AP MLB: https://apnews.com/MLB and https://twitter.com/AP_Sports