SAN FRANCISCO -- The trade rumors and speculation surrounding Giants ace Madison Bumgarner will only intensify as the season inches closer to the July 31 Trade Deadline. One of the teams that is likely to be linked to Bumgarner is the Braves, who got an up close look at what the 29-year-old left-hander can offer on Thursday afternoon.

Bumgarner allowed two runs on six hits over six strong innings, though he came away with a no-decision after the Giants’ bullpen suffered a rare stumble in a 5-4 loss in 13 innings at Oracle Park.

“I thought he threw the ball very well,” manager Bruce Bochy said. “He left the game with the lead, and those are the games we’ve been holding on and winning. We let this one get away. We just couldn’t get the bats going later in the game against their bullpen.”

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Bumgarner, who walked two and struck out six in the 102-pitch effort, had been in line for the win after Steven Duggar put the Giants ahead, 3-2, with a two-out RBI single in the fifth. Tyler Austin added an insurance run with a pinch-hit home run in the seventh, but the Braves came back to tie the game on Austin Riley’s two-run shot off Tony Watson in the eighth.

Riley struck again in the 13th, delivering a go-ahead single to the opposite field off Reyes Moronta to secure a series victory for Atlanta, 3-1. The 22-year-old rookie, who debuted with the Braves last week, went 6-for-17 with three home runs and eight RBIs in four games against the Giants.

“Riley killed us,” Bochy said. “He had some big hits, even off Moronta.”

At 21-28, the Giants continue to trend in the opposite direction of the Braves, who are in the thick of the National League East race and brimming with young talent. The gap between the organizations explains why they could ultimately match up well at the Trade Deadline.

The Braves have long been identified as a logical landing spot for Bumgarner, who hails from North Carolina and could add a valuable veteran presence to Atlanta’s inexperienced rotation in a potential bid for the postseason.

With the No. 3 farm system in baseball, according to MLB Pipeline, the Braves certainly have enough prospect capital to make an offer that could compel the Giants to trade their longtime ace as they look to restock their own pipeline.

The Braves are reportedly one of eight teams on Bumgarner’s no-trade list, though it’s clear he made the choices strategically in order to give himself a little more leverage and control over the process. The other clubs are the Astros, Brewers, Cardinals, Cubs, Phillies, Red Sox and Yankees, all of whom are contenders that could be looking to upgrade their rotation at the Trade Deadline.

It’s worth noting that Bumgarner will likely be motivated to approve a trade, as players who are moved during the season are ineligible to receive a qualifying offer, which likely played a role in depressing the free-agent markets of Dallas Keuchel and Craig Kimbrel, both of whom remain unsigned.

Thursday served as yet another showcase for Bumgarner, who yielded the two lone runs on an RBI single to Ozzie Albies in the fourth and a leadoff home run to Tyler Flowers in the fifth. While Bumgarner has a 4.10 ERA over 11 starts this season, he’s shown an uptick in velocity on his fastball and cutter, a sign that he’s moved past the injuries that sidelined him for large chunks of the past two seasons. He induced a season-high 17 swinging strikes on Thursday, 11 of which came on his cutter.

“I still expect a little more, but that’s a good team over there,” Bumgarner said. “A lot of guys I wasn’t really familiar with. I’ll take that today, for sure. Regardless of personal results and all that, it’s about giving your team a chance to win.”

Williamson wears Platinum Sombrero

Left fielder Mac Williamson’s struggles deepened on Thursday after he went 0-for-5 with five strikeouts, dropping his batting average to .128 over 14 games. He became the fifth Giant to strike out five times in a single game and the first since Brandon Belt on July 8, 2013, against the Mets.

“As a pitcher, when you’re looking up there and a guy is hitting .120 or .130, that instantly gives them pretty good confidence,” Williamson said. “They’re not afraid to throw to me right now. I got plenty of pitches to hit today. I feel like early in the counts, when I do get good pitches, I either take them or foul them off. I haven’t been able to put them in play.”

The Giants had been hoping Williamson would be the answer to their season-long quest for production in left field, but Bochy said the club will discuss how to move forward from here.

“That was a tough day there,” Bochy said. “We’ll huddle up and see what we can do to add some offense here.”