Victor Martinez is tagged out by Oakland catcher Kurt Suzuki with nobody out in the third inning. (AP)

Back in late November, after he had been named as the Red Sox’ third base coach, Tim Bogar described his new position to WEEI.com as “a great challenge.” Thursday afternoon he was reminded of that reality. (See: ‘Tim Bogar braces for the hot seat”)

Bogar was forced to hold his second postgame media gathering of the season, this time after the Sox’ 9-8 loss to the A’s in which he waved two runners in with nobody out, coming away with no runs (and two outs) to show for his efforts.

“Obviously with nobody out, two bad decisions and I got two runners thrown out at the plate,” he said. “Obviously both times I was wrong so I take full responsibility for it.”

The first instance when Bogar ran into trouble came in the third inning, when Victor Martinez barreled around third base from first on Kevin Youkilis’ drive to left. Martinez, who has been battling a sore left big toe, was waved in by the third base coach only to get tagged on the shoulder by Oakland catcher Kurt Suzuki after the A’s made a solid relay from left fielder Eric Patterson to shortstop Cliff Pennington to home plate.

The second occasion occurred in the fourth inning when Jeremy Hermida rifled a single to right field, advancing Darnell McDonald from second. This time there was no cut-off, with outfielder Gabe Gross throwing a strike to Suzuki to nail McDonald, who had experienced a brief knee injury when diving back into first base earlier in the frame.

“I think the first play was a pretty good play by the catcher,” explained Bogar. “Pennington’s got a strong arm, but it short-hopped him and he made a good play and it was a close play at the plate. Obviously the second play, when the ball was hit, I didn’t think it was hit as hard as it was. Sometimes you have to give credit to the other guys, but when there is nobody out you have to make sure they can score and it just didn’t go that way.”

Oakland manager Bob Geren, for one, could understand the decisions.

“The one was a great throw by Pennington. And Suzuki made one of the better plays on the final end of that. That was an incredible athletic play with a great tag and a good call by the umpire,” Geren said. “And Gabe just absolute threw an absolute low rocket from right. He was a quarterback in college, he’s got a cannon.

“It took two incredible plays to get them. I understand why they were being aggressive. It took two absolute perfect plays to get people so more times than not, they’re going to be safe. It just took two incredible plays.”

Bogar insisted that neither injury — Martinez’ toe or McDonald’s knee — factored into his decision-making process.

“It had nothing to do with it,” he said. “They were two decisions I made that didn’t go our way. Obviously I should have learned from the first one.”

Bogar’s most notable mistake prior to Thursday had come on April 16 when he sent Kevin Youkilis with nobody out in a 1-1 game. Youkilis would be gunned down on a relay from Ben Zobrist to Reid Brignac to catcher Dioner Navarro.

“I think we’ve talked before because of my over-aggressiveness. Is it a fault? I guess if it continues to happen, yeah,” Bogar said. “But you know what? Every time I sent a guy at that point I thought I made the right decision. I’m going to live with those results and try to learn from them. You know what? I’m not going to change who I am and how I go about it. I’ll just try to learn and make better decisions.”

Bogar insisted, however, the pair of decisions won’t affect him going forward.

“I’m confident in what I’m doing,” he said. “I’m confident in my decision-making. I feel like I do a good job over there. Today is one of those days where I made two decisions that went the wrong way.

“It’s a job that you have to. Every guy who steps up to the plate you have a decision to make sooner or later. If you keep thinking about what you’re doing and what has happened in the past, you’ll be over there with a lot of stress. Just do my job, keep making decisions, learn from my mistakes and go on.”