MILWAUKEE — Technically, Byron Buxton had another seven days left on his rehab assignment, but the Twins went ahead and optioned the 24-year-old center fielder to Triple-A Rochester on Monday.

Buxton went out and homered in his first at-bat after being optioned.

“We didn’t put a timeline on Buxton from Day 1 when we decided to put him on a rehab, which was the right thing,” Twins manager Paul Molitor said. “It’s not, ‘OK, when this calendar date comes, your time is up,’ and he knows that. Don’t know what’s going to happen. We’ll see if it pays off in the long run whether he actually gets back here quicker.”

If somehow Buxton doesn’t accrue another 13 days of service time this year, he will finish 2018 with less than three full years in the majors. While he would still be eligible for salary arbitration as a Super 2 this offseason, the Twins would then be able to delay his free agency until after 2022, as unlikely as that may be.

Buxton’s left big toe is healthy but his swing still needs work. Even after getting two hits, including a double, on Sunday for the Red Wings, he was batting just .214 with 15 strikeouts through 42 at-bats in Triple-A.

“A lot of guys on the staff reached out (to Buxton),” Molitor said. “I talked to him (Sunday). He’s obviously willing to do what ever we feel is in his best interest. As a player you want to be up here contributing right now. I just told him that the timing is still to be determined.”

TWINS SIGN URBINA

As expected, the Twins opened the 2018-19 international signing period by agreeing to terms with Venezuelan center fielder Misael Urbina.

According to a person with direct knowledge, Urbina will receive a $2.75 million bonus upon passing his physical. The 5-foot-11, 170-pounder, who turned 16 in April, is expected to draw the largest bonus out of Venezuela this year.

According to Baseball America, Urbina has strong defensive instincts, good closing speed and a below-average arm. Scouts are reportedly split on his hitting ability, but he does have pull-side power with a compact swing.

Also expected to sign with the Twins this week are Dominican shortstop Felix Rosa and Venezuelan right fielder Alexander Pena. Pending physicals, both are expected to receive bonuses of $200,000 or more.

The Twins are among six teams with an international bonus pool of $6,025,400. Dominican second baseman Yunior Severino, who signed with the Twins for $2.5 million in December after being declared a free agent by Major League Baseball, counts against the 2018-19 pool.

RIPPLE EFFECT

In order to make room on the 40-man roster for shortstop Jorge Polanco, who was reinstated after serving an 80-game steroid suspension, the Twins designated for assignment outfielder Ryan LaMarre.

The 29-year-old LaMarre was optioned to Triple-A a week ago after posting a .321 on-base percentage in 109 plate appearances. The Twins will have seven days to trade, release or pass him through waivers.

“I really enjoy having Ryan LaMarre around the team,” Molitor said. “He’s (got) energy, he’s unselfish. He’s always willing to try to learn more to become better. He’s a great teammate. Sometimes that’s the way it goes.”

In addition, left-hander Adalberto Mejia was optioned to Rochester after lasting just four innings in his 2018 big-league debut on Saturday in Chicago and infielder Ehire Adrianza was placed on the 10-day disabled list with a strained left hamstring.

Over his past 77 trips, dating to June 6, Adrianza had hit .324 with a .918 OPS while batting hamstring soreness for the past couple of weeks. Adrianza lobbied to stay active, but the Twins felt the condition worsened on Saturday at Wrigley Field.

To replace Mejia right-hander Zack Littell was recalled from Rochester, where he has a 3.00 ERA in 51 innings (eight starts). Littell will work in middle relief for now, but the Twins will need another starter on Thursday at home against the Baltimore Orioles.

LARNACH UPDATE

The Twins continue to talk with the adviser for Oregon State right fielder Trevor Larnach, the 20th overall pick in this year’s draft, but no deal had been struck as of Sunday night.

According to a person with direct knowledge, it’s “still possible” the Twins will sign sixth-rounder Charles Mack, a high school third baseman from New York and a Clemson signee. If they can get him under contract for less than the $253,700 signing slot, Larnach’s bonus offer could increase in advance of Friday’s deadline.

Slot value for the No. 20 pick is $3.12 million, but the Twins might only have about $2.9 million left in their draft pool after going over slot for four other picks in the first 10 rounds.

BRIEFLY

Super utility man Taylor Motter (concussion) was due to take a few swings indoors as well as undergo an ImPACT test. If all went well, he could hit on the field as soon as Tuesday with an eye toward coming off the 7-day concussion DL as soon as Friday.

Wilfran Astudillo, 16-year-old cousin of Twins utility catcher Willians Astudillo, signed with the Blue Jays. The younger Astudillo is the son of Willians’ cousin Franny. When Willians Astudillo signed with the Phillies in 2009, his bonus was $90,000.