In one month, circumstances will have changed.

By the end of September, the contenders will have separated themselves from the pretenders, and the only remaining battles will take place on top of the divisions and in the Wild Card races.

That's right, the postseason is just around the corner.

But until then, it's time for the stretch run. It's time to play ball, and it's time to discover in earnest which teams will be playing in October.

Are you ready for some baseball?

You'd better be.

During the next 35 days we will find out how badly teams want to make it to the postseason and which clubs simply are not good enough to make it there.

During the next seven days, we will see teams reveal their true identities. Can the resilient Yankees take control in the AL East, or is this the week the Rays move past them and stay there for good?

Can the Rangers, a club that has not been to the postseason since 1999, hang on to win the AL West title, or will the A's sneak up and ruin the Texas party?

Exactly how will Manny Ramirez's presence in the White Sox lineup and in the clubhouse impact the race in the AL Central? On another note, which race is more fun to watch: The contest for the NL Central title between the Reds and the Cardinals or the competition between St. Louis slugger Albert Pujols and Cincinnati's Joey Votto for the MVP, and perhaps the Triple Crown?

In other words, which team has the most power and how long can it keep it?

MLB.com set up a special panel to discuss those questions and vote on the top 15 teams each week. Two former Major League players -- Larry Dierker and Jeff Nelson -- are part of the process, as is Carlton Thompson, vice president and executive editor of MLB.com. Former general manager and current MLB.com analyst Jim Duquette, MLB.com director of statistics Cory Schwartz and MLB.com columnist Jesse Sanchez are also part of the group.

Results will be revealed every Monday through the rest of the regular season. Agree? Disagree? Comment down below and become part of the debate.

This Week's Power Rankings
This WeekMovementPower PlayerLast Week
1Even with last week.Yankees

The most talented team in baseball will get stronger during the final month of the season when Alex Rodriguez, Lance Berkman and Andy Pettitte all come off the disabled list. This could be a September to remember.

1
2Moved up from last week.Padres

San Diego has the best record in the NL and it could be the best team in the league. The Padres' hitting has caught up with its superb pitching, a dangerous combination for any opponent.

3
3Moved down from last week.Rays

The stretch run is here, and the race for the AL East title has kicked into high gear. Do the Rays have what it takes to pass the Yankees in the standings and stay there?

2
4Even with last week.Braves

Turner Field has become the place where opposing teams go to have their hearts broken. The Braves' 46-18 record in Atlanta gives new meaning to the term "home-field advantage."

4
5Even with last week.Twins

The competition in the American League has to be shaking its head right about now. Kevin Slowey, Justin Morneau, Jose Mijares and Nick Punto are all on track to return from injury soon, and things could get very interesting very soon.

5
6Moved up from last week.Rangers

Josh Hamilton could lock down the AL MVP Award this month, but questions linger about Cliff Lee. Lee has struggled in his past four starts, especially the past two losses to Minnesota and Baltimore, which combined for 13 runs against him in 10 2/3 innings.

7
7Moved down from last week.Reds

Joey Votto continues to turn heads and is making a strong case for the NL MVP Award. The Reds' bullpen should get a boost this week when Aroldis Chapman gets the call as big league rosters expand on Sept. 1.

6
8Moved up from last week.Red Sox

Don't count out the Red Sox. They'll either sneak their way into the postseason or spoil another team's hopes for the playoffs. They could do both.

9
9Moved down from last week.Phillies

Don't look now, but the Phillies are starting to remind everyone why they've appeared in past two World Series. Remember, the "Roys" didn't come to Philadelphia to miss out on the postseason.

8
10Moved up from last week.White Sox

Manny Ramirez, Paul Konerko, Alex Rios and Carlos Quentin. Those four names in any order are enough make pitchers squirm. Ramirez, a free agent at the end of the season, is playing for a contract, so watch out AL pitchers!

12
11Even with last week.Giants

Buster Posey (strained left forearm) is expected back, but the club really needs its starters to return to form if it is going to have any chance to catch the Padres in the division or the Phillies in for the NL Wild Card.

11
12Moved down from last week.Cardinals

St. Louis has struggled against last-place teams lately and is heading for a showdown this weekend with the Reds. Momentum matters in the final month of the season, and the Cardinals need to find some.

10
13Moved up from last week.Rockies

Jim Tracy's club has not given up on the postseason and will not give in until the final game of the season is over. That's bad news for anybody that plays the Rockies.

14
14Moved down from last week.Blue Jays

Toronto's potent offense is just as powerful as any offense in either league. The Jays lead the Major Leagues with 197 homers. The next closest is Boston with 172.

13
15Moved up from last week.Dodgers

The Dodgers will miss Ramirez's personality and his bat, but he played in only 66 games for them this year. If the Dodgers want to crash the postseason party, they'll have to hit better with runners in scoring position.

Was unranked last week.
On the bubble: A's