OAKLAND -- The Rangers have assured themselves of a playoff spot, but they have still not clinched a division title. Instead, their lead in the American League West is down to one game, the smallest it has been since the first week of the season.If the Rangers don't win one of their final two games, they will find themselves in a Wild Card playoff game on Friday instead of preparing for an AL Division Series. The Rangers found themselves in that precarious situation after rookie left-hander Martin Perez allowed four runs in four-plus innings in a 4-3 loss to the Athletics on Monday night. This is as close as anybody has been to the Rangers since they held a half-game lead on April 11. They are also now tied with the Yankees for the best record in the AL at 93-67. "We're upbeat," catcher Mike Napoli said. "We're not worried about anything. We just have to go out tomorrow and try to win the division." The Athletics clinched at least a Wild Card playoff spot by beating the Rangers. That's something the Rangers did on Sunday night with their victory over the Angels. Now the division title is up for grabs. "We've got to win ballgames," infielder Michael Young said. "Every game has been important for a long time. We've played a lot of tight games and this team has a lot of experience in these games. We'll come out and be ready tomorrow." The Rangers led the division by four games on Sept. 20 but have lost seven of their last 11. They send All-Star left-hander Matt Harrison to the mound on Tuesday to face Oakland left-hander Travis Blackley. A victory would clinch the Rangers' third straight division title. "I have a lot of confidence in my team," manager Ron Washington said. "We played a real good game tonight. They did, too. We just came up short. My team knows what has to be done. We just got beat. We'll bounce back tomorrow." A's rookie right-hander Jarrod Parker helped put off the Rangers' clinching celebration by holding them to three runs on six hits and two walks over six-plus innings while striking out six. But his bullpen was even more effective as the combination of Sean Doolittle, Ryan Cook and Grant Balfour combined to retire nine straight Rangers after Napoli's leadoff home run in the seventh off Parker made it a one-run game. Perez is the Rangers' top pitching prospect and was making his sixth Major League start. It was also his 12th overall appearance. Perez came into the game having allowed a .341 batting average and a .426 on-base percentage in his first inning of a game. Those numbers went up after he allowed six of eight baserunners to reach in the first inning on Monday night. "I put a little too much pressure on myself and accelerated myself in the first inning before I settled down," Perez said. Perez started the night by giving up leadoff singles to Coco Crisp and Jonny Gomes, putting runners on first and second. Perez got Yoenis Cespedes to hit into a double play, moving Crisp to third. But Chris Carter walked and Josh Reddick lined a single to center to bring home a run. Josh Donaldson drew a walk to load the bases and Perez committed a balk to bring home a second run. Perez then got out of the inning by getting Stephen Drew on a fly to right. He also started getting into a rhythm, at least temporarily. Beginning with Drew, Perez retired 10 of 11 batters and that gave his offense a chance to come back. "He did a good job, he really did," Washington said. "That first inning he had some jitters he couldn't control. But he got that third out and settled down." The Rangers got one run off Parker in the third after Napoli walked and Mitch Moreland singled to lead off the inning. Ian Kinsler struck out, but Elvis Andrus lifted a broken-bat single over shortstop that brought home Napoli and moved Moreland to third. Parker kept him there by striking out Josh Hamilton and getting Adrian Beltre on a grounder to second. "Those are the type of situations you have to work and try and take advantage of," Washington said. "We didn't and that was the difference in the ballgame -- that and the balk." Young tied the game with a one-out home run in the fourth, his eighth of the season. But the Rangers would only get two more hits the rest of the night. Perez started the fifth inning by giving up doubles to Adam Rosales and Crisp. That gave the Athletics a 3-2 lead and Scott Feldman came in to pitch. Crisp ended up stealing third and scored on a sacrifice fly by pinch-hitter Brandon Moss. That made it a two-run game. Napoli hit a home run to lead off the seventh to drive Parker from the game, but the A's bullpen made a one-run lead stand up. The Rangers and the Athletics are both in the playoffs, but the division title is yet to be decided.
T.R. Sullivan is a reporter for MLB.com. Read his blog, Postcards from Elysian Fields and follow him on Twitter @Sullivan_Ranger. This story was not subject to the approval of Major League Baseball or its clubs.