Baseball's annual non-waiver trade deadline -- July 31 -- came and went with several high-profile deals. That is not a hard deadline, however. Teams can still make trades after that date. They just have to go through the trade waivers process first. Here's how that works.

The Mariners and Cardinals made a fairly notable waiver trade Wednesday as Mike Leake was sent to Seattle for a lower profile prospect in what amounted to a salary dump. Others like Curtis Granderson, Jay Bruce, Neil Walker, Yonder Alonso, Rajai Davis  and Sean Rodriguez have been traded since July 31. Some pretty big names there.

Another very important trade deadline is approaching this week. Thursday at 11:59 p.m. ET is the deadline for teams to acquire players and have them be eligible for the postseason roster. There are no exceptions. A player has be in your organization -- not necessarily on your big-league roster or even on the 40-man roster, but in the organization -- at 11:59 p.m. ET Thursday if you want him available in the postseason.

As a result, there is usually a rash of smaller trades made in the hours leading up to that 11:59 p.m. ET deadline. It's not often a huge name moves this late in the season, but there is definitely some last-minute roster tweaking. Here's a recap of last year's Aug. 31 trades:

Crisp, Bourn and Salas were on postseason rosters last year. Heck, Bourn started the AL Wild Card Game for the Orioles and Crisp started seven of 15 games for the Indians in the postseason, including Games 6 and 7 of the World Series. These last-minute Aug. 31 moves sometimes wind up meaning more than you may think.

As always, the best Aug. 31 trade candidates are veteran players on non-contending teams, especially impending free agents. A team looking for a depth arm could call the Padres about Jhoulys Chacin or the White Sox about Miguel Gonzalez. Royals southpaw Mike Minor could interest a club looking for a bullpen lefty. Thursday is likely the last chance for the Reds to get something for Zack Cozart.

Although the Aug. 31 deadline does not generate nearly as much buzz or as many exciting headlines as July 31 -- the most famous is probably the Red Sox trading Jeff Bagwell for Larry Andersen on Aug. 30, 1990 -- it is an extremely important date on the baseball calendar. It's the last chance for contending teams to go out and get that one last piece, and have that player be eligible for the postseason roster. Teams can still go out and make trades in September -- September trades are rare, but they do happen -- but that player won't be able to help in October.