Joe Morosi of MLB.com reports that there are some starters on the market that could really help a contender. Morosi writes that the following All-Star caliber starters are on the trade` block. These include Yu Darvish, Ervin Santana, Gerrit Cole, Justin Verlander, Sonny Gray, Ja Happ, Julio Teheran, Dan Straily, and Johnny Cueto.

The ones on the move

The Rangers would be silly to keep Darvish. The four-time All-Star has logged 118.2 innings this year and is set to be a free agent at the end of this season. The Rangers are tied for second in the American League West Division but are 16.5 games behind the Houston Astros with little chance of making the wild card.

The Yankees, Astros, and Dodgers are looking for a starting pitcher. It's unlikely that the Astros will persuade Texas into giving up Darvish as a rental, but the Yankees could use some chemistry with Masahiro Tanaka who is also from Japan.

Gray is likely to be on the move as well. Gray has received interest from the Milwaukee Brewers this season and has been pitching much better. Happ could be flipped. His value is down from last year's 20-4 record, but he does have a 3.54 earned run average on a bad Blue Jays team.

Up in the air

It's unknown of who would want Verlander. It's true that the 34-year-old veteran is on the trading block, but his contract will cause problems. Verlander is set to make $28 million the next two seasons.

Verlander finished second in the Cy Young voting last season, but his earned run average has ballooned to 4.73.

The Pirates could trade Cole if they want to start a rebuild, but Cole could be a building block during that time. He isn't set to be a free agent until 2020. He is just 26 years old and has Cy Young potential. Straily has pitched well this year to a 3.31 earned run average with Marlins, but he is just one of many potential players that could be traded off of that team.

No chance

The Twins have a chance to make the playoffs. Santana is the team's ace, and they are going to ride his coattails until the end of the year. The Twins are just two games back, so it will take more for them to trade Santana. Teheran is not going to be traded either.

The Braves have said they are not going to get rid of their best pitcher.

Finally, Cueto is likely to opt out of his contract at the end of this season. He is having a down year and is set to make a lot of money. There are few teams that will be willing to give up prospects for a player in a down year.