Blockbuster trades generate lots of excitement, but not all rumors turn into reality. Some of the possible trade scenarios that dominated MLBTR early on this season never actually happened. Let's revisit five of those non-trades with an eye on the coming offseason:

1. Justin Upton, Diamondbacks – The Upton rumors have subsided, but I doubt they've disappeared for good. The Diamondbacks don’t appear to have ruled out the possibility of an offseason trade involving Upton, who has a .765 OPS since the beginning of August.
2. Cliff Lee, Phillies – The Phillies aren’t eager to trade Lee, but moving him would create some flexibility for a team with considerable commitments to its 2013 payroll. The left-hander is guaranteed $25MM per season through 2015 and his contract includes a $12.5MM buyout for a vesting option in 2016. The Dodgers, the only team with more 2013 commitments than the Phillies, are obviously not intimidated by his contract.
3. Matt Garza, Cubs – Garza drew considerable interest leading up to the trade deadline, but he hasn't pitched since. A stress reaction in the back of his pitching elbow will sideline him for the remainder of the 2012 season and GM Jed Hoyer expects the right-hander will return in 2013, his final season before hitting free agency. If the Cubs do trade Garza this winter they figure to have less leverage than they did in July, when he appeared to be healthy.
4. Josh Johnson, Marlins – The Marlins reportedly sought a Mark Teixeira-like package for Johnson when they listened to offers for him midseason. He'll earn $13.75MM in 2013, the final year of his contract with Miami. Most teams can handle that kind of commitment for a pitcher coming off of a strong season (3.86 ERA, 140 strikeouts and 51 walks in 165 1/3 innings) so he'll draw lots of interest if the Marlins make him available again. It'd be a surprise if they obtained a franchise-altering collection of prospects for Johnson, however.
5. Chase Headley, Padres – Headley, the National League’s player of the month for August, has been on an extended hot streak since the non-waiver trade deadline. He has hit .331/.369/.653 with 12 home runs in the 31 games he's played, boosting his trade value to new heights. There’s no guarantee Josh Byrnes will look to trade Headley this offseason — the Padres could look to contend — but if he does there will be a long list of GMs interested in seeing what the 28-year-old could do in a more hitter-friendly environment. Headley, who's under team control through 2014, is an offseason extension candidate.

Others such as James Shields, Cole Hamels, Jason Vargas, Carlos Quentin, Alfonso Soriano, Huston Street, Josh Willingham and Justin Morneau get honorable mentions.

It's officially September, but the trading season isn't necessarily over. Here's what you need to know about dealmaking after August.

Trading in September is a lot like trading in August. Players who have cleared waivers can be traded to any team. However, to be eligible for postseason play a player must be on the active roster, disabled list, bereavement list, or suspended list of that club as of midnight EDT on August 31st, as Keith Law explained in this article. Because of that rule, most deals occur before September. 

Trades do happen in September, since acquisitions can help teams reach the playoffs. For example, the Phillies famously traded for Sparky Lyle in September of 1980. Lyle was a major contributor for the '80 Phillies team, even though he wasn't able to play in the postseason en route to the team's first World Series title.

More recently, players such as Kila Ka'aihue, Octavio Dotel and Willie Bloomquist have been dealt in the final full month of regular season play, as MLBTR's Mike Axisa explained three days ago. PTBNLs are often determined in September, too.

A version of this post was first published in 2009.

While teams like the Dodgers and Yankees have already committed to nine-figure payrolls in 2013, others have less than $15MM committed to the '13 roster. Cot’s Baseball Contracts has compiled each team’s payroll obligations for 2013. Here's the list, starting with the largest commitments:

• Dodgers, $193.8MM
• Phillies, $133.1MM
• Yankees, $119.1MM
• Cardinals, $92.8MM
• Angels, $92.3MM
• Tigers, $90.2MM
• Rangers, $84.4MM
• White Sox, $83.3MM
• Giants, $81.0MM
• Reds, $74.1MM
• Twins, $68.3MM
• Marlins, $67.5MM
• Blue Jays, $61.3MM
• Nationals, $58.6MM
• Diamondbacks, $55.0MM
• Mets, $54.5MM
• Orioles, $53.2MM
• Brewers, $52.4MM
• Rockies, $46.5MM
• Red Sox, $45.6MM
• Cubs, $41.8MM
• Mariners, $40.5MM
• Royals, $34.9MM
• Pirates, $27.9MM
• Padres, $26.0MM
• Athletics, $23.0MM
• Rays, $18.6MM
• Braves, $15.2MM
• Indians, $11MM
• Astros, $5.5MM

Please note that these figures don't include club or vesting options or figures for players whose salaries will be determined via the arbitration process. The totals include commitments to players no longer in the organization.