• Explaining possible tiebreakers for postseason
If the Rangers win on Sunday, they win the division, regardless of what the Astros do. But If the Astros win and the Rangers lose, they would then play a one-game tiebreaker to decide the AL West champ on Monday in Arlington, based on the Rangers winning the season series between the clubs (13-6). The loser of that game would face the Yankees in the AL Wild Card Game, with the venue depending on whether New York wins on Sunday.
If the Astros lose and the Angels win on Sunday, they would be tied for the final Wild Card spot and play a one-game tiebreaker on Monday at Minute Maid Park, based on the Astros winning the season series between the teams (10-9). The winner of that game would face the Yankees in the Wild Card Game.
The Astros are also only a game behind the Yankees. If Houston wins a Wild Card spot and finishes tied with New York, the AL Wild Card Game would be at Minute Maid Park, as the Astros won the season series, 4-3.
• Standings | Wild Card race
For veteran catcher Jason Castro, a chance to clinch a postseason spot entering the final game of the season is something he's waited a long time to do. It was only two years ago when Castro was on crutches in the clubhouse watching the Astros lose 15 in a row to cap a 111-loss season.
"To be in this position at the end of the year is what you play for, what makes it fun," Castro said. "It's one of the most exciting seasons of my career. I'm happy about, but we're not done. We're still hungry, and we still have a lot left to prove."
Relief pitcher Pat Neshek has been through this before a few times. Last year, he was with the Cardinals when they clinched the National League Central title on the final day of the season. He was on the 2012 A's, who swept the Rangers to win the AL West at the end of the year. In '08, he was with the Twins when they lost a one-game tiebreaker and were eliminated, and then clinched a playoff spot by winning a one-game tiebreaker the next year.
"That's what makes it fun," he said. "Everybody knows what's on the line, and they're giving it everything."
Brian McTaggart is a reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.