As October nears and MLB playoff races tighten, teams must do whatever they can to bolster their rosters. Those teams that have promoted prospects are hoping their young players can provide a spark and make a difference, potentially bringing them to the playoffs.

In the coming weeks, there will be lots of talk of potential moves that will send All-Stars to contenders in the return for top minor league prospects. But before MLB teams commit to sending their young, groomed talent to a rebuilding team for a two-month rental, they should look at their value in the major leagues now.

We’ve already seen some teams improve their rosters from within. The Chicago Cubs and Chicago White Sox have relied on their young prospects in the past month or so.

The Cubs promoted catcher Willson Contreras who has rewarded them by playing in 27 games, hitting .289 five home runs and 16 RBIs. The White Sox brought up Tim Anderson who’s started 32 games while hitting .279.

Sometimes a young prospect can be the difference maker in a run to the World Series. We saw the Boston Red Sox call up then highly touted shortstop Xander Bogaerts in August of 2013. The now All-Star ended up batting .296 in the playoffs that year, contributing with nine runs and a couple of very important at-bats.

In order for a player to be eligible for playoff rosters they must at least be on the 25-man roster or on the disabled list by midnight on August 31.

The following are recent players who have been promoted that can make a big difference to their club’s success come August, September, and October. Some of these players have been up and down, and may not be getting a lot of playing time, but they can contribute in other ways. The list will have the most important player to their respective club’s success listed at number one.