Many frustrations have surrounded the Phillies' season and one toward the top of the list is the lack of production from their perceived trade candidates.

GM Matt Klentak brought in a handful of veterans in the offseason with the intention of slightly improving the big-league club while also giving himself a chance to net a few lottery-ticket prospects around the trade deadline.

Unfortunately, more has gone wrong for the Phillies' veteran acquisitions than has gone right. Let's go one by one.

RHP Jeremy Hellickson (owed approximately $5.7 million after July 31)

Whatever trade value Hellickson had last summer and earlier this season has vanished. He was rocked again Wednesday as his ERA rose to 4.91 (see Instant Replay).

Since May 1, Hellickson has allowed 12 home runs in nine starts and his opponents have hit .310 with a .993 OPS. Add that to his hefty 2017 price tag and the result is a player who may be tradable but won't net you much.

Another key difference between this year and last is that Hellickson was arguably the top starting pitcher on the trade market last summer. This summer, there are many better options in Gerrit Cole, Sonny Gray, Jose Quintana, Jason Vargas and Jaime Garcia, just to name five.

Maybe Hellickson reels off five or six dominant starts before the deadline to reestablish the trade value, but it sure looks like the Phillies swung and missed with him two years in a row.

RHP Pat Neshek (owed ~$2.2 million after July 31)

It's pretty clear that Neshek will be moved. He knows it himself (see story).

He's been the Phillies' best pitcher this season, allowing two runs in 24 innings for a 0.75 ERA. He's allowed 15 hits, walked four and struck out 22.

He also has shown the capability to retire big-time bats. Daniel Murphy, Ryan Zimmerman, Freddie Freeman, Giancarlo Stanton, Nolan Arenado and Yoenis Cespedes are a combined 0 for 12 with four strikeouts this season against Neshek, who's made a career out of keeping powerful righties off-balance.

But as good as Neshek has been, don't expect the Phillies to get a significant prospect in return for him. He's a 36-year-old setup man on an expiring contract.

Looking at last year's trade deadline, the deal involving a player most similar to Neshek was the Brewers' trade of Will Smith. Milwaukee traded Smith to the Giants for catcher Andrew Susac and former Giants first-round pick Phil Bickford, a pitcher with upside who's far from a sure thing.

Smith was 10 years younger than Neshek last summer but carried a similar track record — 3.22 ERA the previous three seasons as a setup man ... a nice piece and the kind of player who helps a team but doesn't dictate its success.

Susac, a right-handed hitting catcher with a decent bat, was 26 at the time of the trade and had played in 87 big-league games. He's an Andrew Knapp-type.

For Neshek, the Phillies will likely either get a bench piece or every team's favorite lottery ticket: a Single A arm with upside.

INF/OF Howie Kendrick (owed ~$3.3 million after July 31)

The trade value of Neshek and Kendrick is similar. Two guys with lengthy track records of being pretty good. Kendrick has had a great first half, hitting .340/.398/.500 with seven steals.

Like Neshek, Kendrick's contract is up after the season. Like Neshek, Kendrick should bring back a modest or slightly above-average return.

Looking at the last few trade deadlines and offseasons, the trade most similar to one involving Kendrick might be when the Phillies dealt Chase Utley to the Dodgers in 2015. At that time, Utley was three years older than Kendrick and hitting just .217, but Los Angeles looked at him as a helpful piece with postseason experience, unparalleled work ethic and strong leadership skills. Those final two pieces mattered greatly to a young Dodgers team.

In exchange for Utley, the Phillies got a 4-A utilityman in Darnell Sweeney and right-handed starting pitching prospect John Richy, who was drafted in the third round the year prior.

The Phillies' return for Kendrick should be better but not much better. One advantage the Phillies have here is that Kendrick plays so many positions — left field, second base, first base, third base. There will be no shortage of teams interested in acquiring him.

RHP Joaquin Benoit (owed ~$2.5 million after July 31)

Benoit just has not been the pitcher the Phillies thought they were getting. From 2010 through 2016, he had a 2.40 ERA and 0.98 WHIP with 10.0 strikeouts per nine innings and 2.8 walks.

This season, he has a 4.56 ERA in 25 appearances with a 1.18 WHIP, 8.0 strikeouts per nine and 4.6 walks. His control has been a bit erratic, and though 20 of his 25 appearances have been scoreless, the other five have really hurt.

Benoit was traded last summer by the Mariners to the Blue Jays straight-up for Drew Storen in a change-of-scenery deal involving two struggling relievers. Benoit went on to allow one run in 23 2/3 innings with Toronto.

I do expect the Phillies to move Benoit but unless he has a big turnaround, they might have to eat all of his remaining money just to bring back something of substance.

OF Michael Saunders (owed ~$3 million after July 31)

This has been a very disappointing signing. It's gotten so bad for Saunders that he's lost everyday playing time and has fallen below Daniel Nava in the pecking order of who can help most on a given night.

The Phillies guaranteed the 30-year-old Saunders $9 million and hold a club option for next year at $10.5 million. There's no chance in hell they exercise that option unless he has a second half as good as this first half was bad.

That's assuming he's even on the roster come the second half. Klentak was asked about Saunders on Wednesday and brought up his track record of streakiness, saying he's known to get extremely hot and extremely cold and when he's hot, he can carry a team for a month.

That seemed like a bit of an exaggeration, but through June 17 last season (right around this time), Saunders was hitting .314 with 17 doubles, 15 homers and a .999 OPS.

The thing is, at this point he'd have to get insanely hot for a month and a half to convince a team to trade for him. Otherwise, he's a fourth outfielder at best on a contender. And the Phillies aren't even playing him every day anymore to give him that opportunity.

Sadly, Saunders is more of a DFA candidate than a trade candidate.

RHP Clay Buchholz

Let us never forget Buchholz's legendary Phillies career: 7 1/3 innings, 19 baserunners, 10 runs, one season-ending injury, $13.5 million.

The Phillies paid Buchholz more this season than they paid Odubel Herrera, Maikel Franco, Aaron Altherr, Tommy Joseph, Cesar Hernandez, Freddy Galvis, Cameron Rupp, Knapp, Aaron Nola, Jerad Eickhoff, Vince Velasquez and Hector Neris combined.