CINCINNATI – Major League Baseball's international signing period begins Thursday, and it won't take long for the Twins to spend all of their allotted money. In fact, it will be done with one signing.

Barring a late change of heart, the Twins are set to agree to terms with Dominican shortstop prospect Wander Javier for about $4 million, according to a person with knowledge of the deal. Javier has some of the best tools at his position in the international talent pool, including the potential to hit for power. Some who have scouted him have worried that he won't stick at short, but his offensive potential makes him coveted.

The Twins have been going after Javier for several months and have been considered to be the front-runner to sign him. It would be a huge upset if they don't land Javier.

MLB.com ranks Javier as the eighth-best international prospect. Baseball America ranks him ninth.

If Javier does sign for $4 million it will be a club record bonus for an international player, surpassing the $3.1 million the club signed Miguel Sano for in 2009.

It also will eat up all of the $3,948,500 the Twins have been allotted in bonus money. If Javier costs them $4 million, they would have to pay a tax on the $51,500 overage. If the Twins want to sign other players, they would have to trade for more pool money.

The official signing isn't expected Thursday. A background check, medical exam and the visa process must take place first. The Twins could announce an agreement, though.

Vargas to Chattanooga

Even before the Twins spent the last week in National League parks, Kennys Vargas wasn't getting steady at-bats. And the Twins just don't feel he's the force he needs to be.

So on Wednesday the Twins optioned Vargas to Class AA Chattanooga, and will summon Sano from the same farm club in time for Thursday's game at Kansas City.

"I think in [Vargas'] situation the at bats haven't been consistent enough to where we feel I can get them for him up here," Twins manager Paul Molitor said. "So he's going to go down. It's a good fit for him to go there as far as they have been hurting for a first baseman. It will give him a chance to play a lot defensively and get consistent at bats."

Vargas is batting .244 with five home runs and 15 RBI in 46 games. In 17 games after being recalled from Class AAA Rochester, Vargas batted .235 with two home runs and five RBI with no walks and 17 strikeouts.

"He's had a couple moments since he's been back," Molitor said. "Just hasn't been to where we feel he's a guy you want to get run production from."

Six-man rotation an option?

The Twins have been lukewarm about considering a six-man rotation as an option when righthander Ervin Santana joins the club on Sunday and starts against the Royals.

Santana could get two starts before the All-Star break, then the Twins could reassess the situation during the break. The Twins have indicated that they haven't talked much about using a six-man rotation, but that might be changing as Santana's 80-game suspension for violating the league's drug policy ends Saturday.

"We have options about the rotation, whether we're going to try to go six-man to the break or if we're going to go five," Molitor said. "Are you going to move a guy, if you do go five, to the bullpen or are you going to move him out? There's a lot of things you can look at as options."

Santana looks ready to join the rotation. He was 3-0 with a 1.74 ERA in three starts at Triple-A Rochester. He could be a boost to a rotation that hasn't been shabby.

But how will the Twins add Santana?

"I haven't had a chance to talk to [Rochester manager] Mike Quade or [pitching coach] Marty Mason," Molitor said. "I just looked at the numbers and they kinda jump out at you. A night in which he was efficient, obviously effective and command must have been good. He didn't walk anybody.

"I think everyone is excited to know that we're getting a pitcher of Ervin's caliber back here to join our club. [Trevor May's] job is to look at the big picture. Right now he's called upon to give us a good start and hopefully try to help us win."

Etc.

• After being scratched from Tuesday's starting lineup because of illness, outfielder Shane Robinson was able to start in left Wednesday. But he was hit by a Johnny Cueto pitch in the fifth and left the game after the sixth because of a left elbow contusion.