Vaughn underwent successful left hamate bone surgery Monday, Adam McCalvy of MLB.com reports.

Vaughn suffered the injury Opening Day and landed on the 10-day injured list Saturday after tests revealed a fracture. The Brewers hope he will be ready to return around mid-May. Jake Bauers and Gary Sanchez will handle first base for the Brewers while Vaughn is sidelined.

Steer is not in the lineup for Tuesday's game against the Pirates.

Steer is just 1-for-13 at the plate to start the season, so he'll get a day to regroup. Will Benson is handling left field and batting sixth in Steer's stead.

Santana started at first base and went 0-for-3 with a walk in Monday's 9-6 win over the Tigers.

Santana was in the lineup against a right-hander after Pavin Smith (elbow) was placed on the 10-day injured list Monday. The switch-hitting Santana, in theory, could start against pitchers of either hand, but it's uncertain how manager Torey Lovullo wants to handle first base going forward without Smith. Tim Tawa and Ildemaro Vargas are also options. Santana is 1-for-12 through four games played in the regular season.

Diaz went 2-for-4 with a solo home run in Monday's 3-2 win over the Brewers.

Diaz led off the game with a solo blast off Kyle Harrison, and he later singled off Harrison in the second inning. The veteran designated hitter is swinging a hot bat to begin the season, as Diaz is 11-for-20 with one double, one home run, six RBI, four runs scored and a 1:1 BB:K through four contest.

Kayfus is not in the Guardians' starting lineup against the Dodgers on Monday.

Kayfus will take a seat for Monday's series opener while the Guardians roll with Steven Kwan, Daniel Schneemann and Angel Martinez in the outfield from left to right. Kayfus went 0-for-8 with two walks, one run and four strikeouts across three games against the Mariners this past week. He also struggled in his start in left field Sunday, which could limit the amount of at-bats he sees until he shores up that part of his game.

Hoskins is not in the Guardians' starting lineup against the Dodgers on Monday.

Hoskins opened the regular season strongly, going 3-for-3 with one double and one run scored against the Mariners on Thursday before following that up with an 0-for-3 performance with two strikeouts Friday. He will not be in the Guardians' lineup for a third consecutive game, with Kyle Manzardo starting at first base while Chase DeLauter serves as the designated hitter for Monday's series opener.

Mets manager Carlos Mendoza said Monday that Polanco is dealing with a sore Achilles but feels well enough to serve as a designated hitter, Anthony DiComo of MLB.com reports.

Polanco is in the Mets' lineup at DH on Monday in St. Louis and could remain in that slot for a bit as a precaution. Jared Young is getting a start at first base Monday in Polanco's place, but it should be Brett Baty getting the bulk of the reps there until Polanco is able to play the field. Baty is starting in right field Monday.

Stewart went 2-for-2 with a walk, a double and a run scored in Sunday's 3-2 win over the Red Sox.

There was no let-up for Stewart in the third game of the season. He's now had multiple hits and reached base at least three times in all three games, going 7-for-10 with three walks, zero strikeouts and more extra-base hits than singles. He also showed advanced baserunning Sunday, advancing to second base on a flyout to center field, which put him in a position to reach third base when the next batter singled to left field.

Steer started at first base and went 1-for-4 in Sunday's 3-2 win over Boston.

Steer made his first start of the season at first base after serving as the left fielder Thursday and Saturday. The plan announced this spring, when Steer started at five different positions, was that he would primarily play left field but could also slot in at various spots. In addition to his starting positions thus far, Steer also moved mid-game Saturday to first base and then third base. That roster flexibility helps manager Terry Francona navigate in-game situations, while also ensuring Steer gets a full game of plate appearances.

Kayfus started in left field and went 0-for-2 in Sunday's 8-0 loss to the Mariners. He was also hit by a pitch.

Kayfus made his second career big-league start in left field and it showed on a couple of balls that led to Seattle rallies. Both were hit by lefties that have strong pull tendencies, and Kayfus had to range far from the gap in left-center to make the plays but couldn't. "He was in the right position," manager Stephen Vogt said of Kayfus to Tim Stebbins of MLB.com. "They had a couple of balls that found the line. It's a relatively new position for CJ. A couple of unfortunate plays that went their way. They made us pay for them." It was the first instance of Vogt's decision to have four-time Gold Glove winning left fielder Steven Kwan play center field. The position switch was designed to inject more offensive punch into the lineup at the outfield corners. One unfortunate night may not impact Vogt's decision, but continued issues in left field could result in a reduction of playing time for Kayfus.