The Pittsburgh Pirates continue to win -- six in a row after beating the Mariners 4-2 with two ninth-inning runs on Wednesday and finishing off a 7-2 road trip against the Reds, Angels and Mariners.

With a makeshift rotation filling in the gaps with A.J. Burnett and Wandy Rodriguez currently on the disabled list, manager Clint Hurdle and pitching coach Ray Searage continue to go to the pen early and often. They pulled starter Jeanmar Gomez, in his first start since coming of the DL, after just 81 pitches and five innings, but with a 2-1 lead Hurdle wanted to put the game in the hands of his relievers. Justin Wilson did allow a game-tying home run in the sixth to Raul Ibanez, but Vin Mazzaro pitched two scoreless frames and Mark Melancon got his second save filling in for Jason Grilli.

Justin Wilson ranks No. 3 among relievers for total pitches. Jayne Kamin/USA TODAY Sports

Gomez has made seven starts after beginning the season in relief, but those 81 pitches were actually his most so far. That's the philosophy Hurdle and Searage have followed all season: It's never to soon to go to the pen.

"He gave us the innings we needed and got to the part of the game we're hoping to get to with the lead." Hurdle said. "He was effective again -- real nice job."

The Pirates are averaging 3.55 relief innings per game, second most in the majors behind Toronto, but the Jays have had to use their pen out of necessity; until recently their rotation had been awful. The Pirates actually have the second-best rotation ERA in the majors.

The Pittsburgh bullpen is now 18-10 with a 3.06 ERA. But is it being overworked? Only Astros relievers have thrown more pitches. But let's look at the individuals and focus on total pitches rather than innings.

Justin Wilson: 723 pitches, No. 3 in majors

Jason Grilli: 585 pitches, No. 28

Tony Watson: 575 pitches, No. 31

Vin Mazzaro: 556 pitches, No. 44

Mark Melancon: 537 pitches, No. 56

Bryan Morris: No. 14 since his April 30 recall

That's five in the top 60 when the statistical average would suggest two, plus Morris, who has thrown 32 innings in 21 games since April. Wilson has been the workhorse, but the rookie lefty was a starter in the minors, not that that guarantees he'll hold up all season. Melancon is on pace to appear in 81 games and Grilli 78, but as you can see from the pitch totals Melancon in particular has been very efficient, averaging just 13.7 pitches per outing.

I wouldn't say the bullpen is being overworked, but I would say it's something to watch. You don't want a repeat of what happened to the Braves in 2011, when the bullpen had the third-most innings in the majors but tired down the stretch and went 3-9 in September as the Braves blew a playoff spot. Grilli, after giving up five hits and three runs in his last outing, was given a third straight day off, so maybe you're seeing Hurdle back off him a little.

Everyone think the Pirates need to add a bat, and they probably do. But acquiring another trustworthy bullpen arm would be a cheap addition as well.