The Seattle Mariners head toward the trade deadline this season in playoff position with a decent cushion and carrying the weight of MLB's longest playoff drought. Given the history of general manager Jerry Dipoto -- he's not bashful when it comes to trades -- you can bet the Mariners will try to pull off some deals before the July 31 deadline. 

The rub here is the Mariners are mostly void of top-flight minor-league talent, so it's not as if Dipoto is working with the prospect currency of, say, the Dodgers. He has, however, shown the ability to be creative and add at the margins in his time in Seattle. As such, don't expect a home run of a deal. A nice, strong, line-drive single isn't out of the question, and sometimes that's all you need. 

Trade needs

With Mike Zunino nursing an ankle injury, perhaps they could stand to add a veteran catcher to the mix. Someone like Rene Rivera. It's just that this isn't a glaring need worth a deep dive. The Mariners also get Robinson Cano back -- PED stigma and all -- for the final six weeks or so, and that's an offensive upgrade. Everyone can always use bullpen depth and the Mariners are no different. 

Really, in glancing around the roster and knowing that the Mariners can't really swing a move for a star-type player, it looks like a rotation upgrade here with a veteran is the best bet. James Paxton is pitching like an All-Star (snub) while Wade LeBlanc has been very good, Marco Gonzales has been good and Mike Leake is serviceable. Felix Hernandez has been bad, but he's likely not going anywhere. Still, adding an arm to the mix here to guard against injury or a LeBlanc backslide would be a good idea. 

Keeping in mind the Mariners can much more easily take on money than cough up big-time prospects, we're looking at veterans in a rental situation. Which is fine! A "rental" player can help greatly and there's no reason for a negative connotation. 

Possible fits

Cole Hamels
SD • SP
ERA4.28
WHIP1.36
IP103.0
BB39
K106
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The veteran lefty at this point in his career likely doesn't cost much more than money and won't be much better than league average or slightly above, but, again, this is a fit for the Mariners. Also, not many pitchers on the Mariners have significant postseason experience while Hamels has made 16 playoff starts (7-6, 3.48 ERA). Some people love playoff experience, so those would consider Hamels a plus here. 

J.A. Happ
STL • SP • #34
ERA4.29
WHIP1.19
IP109.0
BB35
K121
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Would they go back to this well? Happ wasn't very good at all for the Mariners in 2015 before they traded him to the Pirates, but that's when things turned around for him. His 11 starts in Pittsburgh produced a 1.85 ERA and he's been good for the Blue Jays since. He's 35 and hits free agency after the season, but the Mariners need the wins now. 

Kyle Gibson
STL • SP • #44
ERA3.42
WHIP1.23
IP115.2
BB46
K114
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He's 30 and hits free agency after the season. Gibson has posted an ERA of over 5.00 in his last two full seasons, but this season he's enjoying the best year of his career with a 3.59 ERA (116 ERA+). He probably wouldn't cost much and gives them another capable starter. 

Matt Harvey
BAL • SP • #32
ERA4.80
WHIP1.29
IP86.1
BB22
K64
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The Reds only needed to cough up a catcher they didn't want anymore to get Harvey away from his bad marriage in Queens. Should they flip him? He's been pretty good overall with the Reds and pitched to a 2.48 ERA in his last five starts. I know the Reds are going well right now, but Harvey is a free agent after the season and they are too far back to believe they are contending this year. Unless they think they can sign him to an extension, strike while the iron is hot. Dipoto would be wise to keep in contact here. 

James Shields
CHW • SP • #33
ERA4.53
WHIP1.28
IP119.1
BB47
K85
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Shields actually has a club option for 2019, so it's possible he could turn into more than a rental. He was bombed on July 7 in Houston, but before that, Shields had pitched to a 3.15 ERA in his previous 10 starts. He's a workhorse who could eat innings, and that's definitely something the Mariners could use down the stretch. 

Tyson Ross
TEX • SP
ERA4.32
WHIP1.27
IP108.1
BB43
K97
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He might be too risky, as the Mariners are looking for stable rotation options and he's injury prone. Still, Ross is having a decent season for the Padres and might be worth a look.