The Athletics selected Muncy's contract from Single-A Lansing on Thursday.

In addition to claiming a roster spot, Muncy will open the season as the Athletics' primary second baseman with Zack Gelof set to miss the first several weeks of the season after undergoing wrist surgery. The 22-year-old Muncy ended spring training with a .282 batting average and .768 OPS, which falls in line with what fantasy managers can expect from him at the plate if he can hit the ground running the majors.

The Orioles included Mateo (elbow) on their season-opening 26-man active roster, and he'll be available off the bench in Thursday's game against the Blue Jays.

Just one day earlier, Matt Weyrich of The Baltimore Sun noted that Mateo didn't have a locker in the visiting clubhouse at Rogers Centre, which seemed to suggest that the 29-year-old wouldn't be included on the Opening Day roster after logging just 11 at-bats in the Grapefruit League while recovering from UCL reconstruction surgery on his non-throwing elbow. However, Mateo told Rich Dubroff of BaltimoreBaseball.com that he feels ready to play after logging extra at-bats in Florida in recent days, and the Orioles are apparently confident enough in his health, too. Mateo projects to handle a utility role for the Orioles, with most of his starts likely to come against left-handed pitching.

The Angels placed Neto (shoulder) on the 10-day injured list Thursday, Rhett Bollinger of MLB.com reports.

The 24-year-old continues to rehab from offseason shoulder surgery and is now officially on the injured list, as expected. According to MLB.com, manager Ron Washington said Tuesday that Neto isn't ready to play in games and has "no date" for his return, so it's unclear when he may be able to make his 2025 debut. Kevin Newman, Tim Anderson, Nicky Lopez and Kyren Paris are all candidates to see time at shortstop with Neto sidelined for at least the first couple weeks of the season.

The Yankees selected Reyes' contract from Triple-A Scranton/Wilkes-Barre on Thursday.

Reyes earned his spot on the Yankees' Opening Day roster through an excellent performance in the Grapefruit League, slashing .311/.418/.467 with five RBI, eight runs scored and two stolen bases through 55 plate appearances. He figures to come off the bench most days while in the Bronx, but his ability to play every position in the field improves his chances of occasionally cracking the starting lineup. Jake Cousins (elbow) was placed on the 60-day IL in a corresponding move.

The Orioles placed Henderson (intercostal) on the 10-day injured list Thursday.

Henderson had been held out of the Orioles' spring lineup since late February due to a right intercostal strain, but he shouldn't be in store for a lengthy stint on the shelf to begin the season. Manager Brandon Hyde said Thursday that the 23-year-old will begin his rehab assignment when Triple-A Norfolk opens its season Friday, according to Danielle Allentuck of TheBaltimoreBanner.com. Assuming Henderson doesn't run into any setbacks during his time with Norfolk, he could be able to make his season debut April 3, when he's first eligible to come off the IL.

Seager (calf) will start at designated hitter and will bat second in Thursday's season opener versus the Red Sox.

Though Seager's availability for Opening Day wasn't in much doubt after he took live batting practice Wednesday without incident, Rangers manager Bruce Bochy was unsure whether the five-time All-Star would be able to play shortstop Thursday while he manages a sore calf. Per Jeff Wilson of AllDLLS.com, Seager was able to do some light running in the outfield earlier Thursday, but the Rangers ultimately chose to exercise some caution by deploying him in a non-defensive role in the first game of the season. Josh Smith will draw the start at shortstop in the opener, but Seager could resume playing in the infield at some point this weekend.

The Red Sox plan to assign Mayer to Triple-A Worcester prior to Thursday's season opener versus the Rangers, Sean McAdam of MassLive.com reports.

Though manager Alex Cora didn't dismiss the possibility of Mayer breaking camp with the big club even in the latter stages of spring training, the 22-year-old infielder always appeared likely to begin the season at Triple-A. Mayer will be joined at Worcester by another elite prospect in outfielder Roman Anthony, while second baseman Kristian Campbell will be the first of the Red Sox's "Big Three" prospects to reach the big leagues. Though Mayer impressed with a .983 OPS in Grapefruit League play, the Red Sox will likely want the shortstop to find some success at the Triple-A level early on in the season before giving him the call to the majors. Mayer could also get some more exposure to second base and third base at Worcester in an effort to increase his versatility and potentially expedite his arrival to the majors.

The Cubs placed Brujan on the 10-day injured list Tuesday due to a right elbow sprain.

Brujan sustained the injury over the weekend, when he attempted to make a defensive play. He'll be eligible to come off the IL on Wednesday, though it's unclear if he'll be ready to play by then. Once activated, Brujan is projected to fill a utility role for the Cubs.

According to Angels' manager Ron Washington, Neto (shoulder) isn't ready for game action and has "no date" for his return, per MLB.com.

Neto hasn't necessarily had a setback -- it's long been expected that he'd open the season on the injured list -- but fantasy managers who are stashing the talented young shortstop will need to wait a bit longer to learn of a clear timeline for his return. It remains in play for Neto to return to big-league action at some point in April, especially since he was recently described as being "ahead of schedule" in his rehab from last November's right shoulder surgery, though Washington added that the 24-year-old will see some work in minor-league rehab games before making his season debut for the Angels. While Neto remains out, Kevin Newman, Tim Anderson, Nicky Lopez and Kyren Paris could all log time at shortstop for the Halos.

The Twins placed Lee (back) on the 10-day injured list Wednesday due to a lumbar strain.

Lee's back began to tighten up on him toward the very end of spring training, and he won't be able to make it back for Opening Day. Reps at third base will likely be handed down to Jose Miranda and Willi Castro while Lee and Royce Lewis (hamstring) are out, but Lee should be able to take over at the hot corner once he returns.