Update: Now confirmed by the Tigers.
His brother may have unintentionally broke the news on Twitter when he tweeted, "Felicidades a mi hermano Lester Oliveros por ese llamado al big show!!" Translated, that means roughly, "Congratulations to my brother Lester Oliveros on his call up to the big show." Credit goes to the Toledo Blade's John Wagner and our own commenter Erin of Tigers Amateur Analysis -- SaberRoseTiger -- for this information. It has not been confirmed by the Tigers, however Wagner has confirmed the information.
A corresponding move on the Tigers' side is not known. However, Wagner and TigsTown.com report 2010 first-round pick Chance Ruffin has been promoted to the Mud Hens. Without a doubt, the Tigers bullpen was pushed to the brink during the Mets series, as Detroit gave up 30 runs during the first two games and only stopped the skid when Justin Verlander took the mound. However, it is difficult to immediately come up with the scenario that opens the spot on the team for Oliveros. There have been no rumors of a trade reported by any source. It's possible a player could be headed to the disabled list. The most popular speculation centers on Al Alburquerque, who suffered elbow pain earlier in the month after throwing a slider. He allowed three runs to the Mets on Wednesday.
UPDATE: Fox Sports' Jon Paul Morosi reports Alburquerque will be placed on the DL with elbow inflammation.
As for Oliveros: His numbers are not particularly impressive in Toledo this year. He has walked 5.2 batters per nine innings while striking out 8.7. However, across two partial seasons spent in Double-A he struck out 13.7 per nine innings while walking about 5.4. Essentially, he strikes guys out but has problems with control. Same story as, well, every young Tiger who has passed through the Tigers bullpen this year, it seems.
Only days ago, Matt Wallace wrote about him at BYB:
"Oliveros would seem to serve as evidence that while there isn't as much of a difference between the Eastern League and International League as many would believe, there's still a difference. He was just killing it in Double A when he was promoted but success didn't come as easily in Toledo. Aside from a three run outing last Wednesday, he's been pretty effective over the past month. So it's possible he's been able to make some adjustments to the higher level of competition."