OAKLAND >> Atlanta Braves first baseman Matt Olson wore a red T-shirt inside the visiting team’s clubhouse at the Coliseum on Monday. On it was a caricature of a smiling Sean Murphy, wearing an outsized hat with the No. 12 on it as he sat at a desk working on a computer.

“We’re still not sure,” Olson said, “what the computer is (all about).”

Fair to say that Murphy, dealt by Oakland to Atlanta last December as part of a complex, three-team deal, has fit right in on a Braves team that leads the National League East and has designs on winning the World Series for the second time in three years. The deal happened eight months after Olson was shipped by the A’s to Atlanta for four players, including catcher Shea Langeliers.

“I don’t know if I was sort of surprised at the moment, but it was a new chapter, I guess,” Murphy said of the trade before the Braves played the A’s on Monday, “but also disappointed to be leaving my friends in Oakland. So, mixed emotions for sure.”

While Olson and Murphy are flourishing in their current environment, the A’s, at 10-45 before Monday, are on pace to finish 2023 with the worst record in the modern era of Major League Baseball.

There are myriad reasons for the A’s dismal record, but the so far modest returns on the Olson and Murphy deals have no doubt had an impact.

From the A’s perspective, Langeliers appears to be the most promising part of the Olson trade, which also netted pitchers Ryan Cusick and Joey Estes, and outfielder Cristian Pache. Langeliers has experienced some growing pains in his first full MLB season, as he entered Monday with a .207 batting average with seven homers, 23 RBI, and a .664 OPS in 46 games this season.

Cusick, 23, and Estes, 21, are both at Double-A Midland and are rated as the A’s 19th and 20th-ranked prospects by MLB Pipeline, respectively. Pache, after a brief stint in Oakland last season, was traded in March by the A’s to Philadelphia for reliever Billy Sullivan, 24, now at Triple-A Las Vegas.

“We talk a lot about pitch selection, pitch calling, handling the staff, leadership roles, really taking ownership out there on the field,” A’s manager Mark Kotsay said when asked about areas of growth he wants to see from Langeliers. “At the plate, he’s continually trying to make adjustments. The fastball has been an issue right now at the top of the zone for him.”

The Murphy deal netted lefty starter Kyle Muller, who was optioned to Las Vegas on May 23 after he collected an 8.04 ERA in 10 starts, pitcher Freddy Tarnok, and catcher Manny Piña. The A’s also received outfielder Esteury Ruiz from Milwaukee as part of the three-team trade.

Ruiz had an MLB-best 27 stolen bases before Monday’s game and like Langeliers, could be a central figure for the A’s in future seasons. Tarnok, 24, is considered the A’s fifth-best prospect by MLB Pipeline and is recovering from a right shoulder strain, but Piña, 35, is out indefinitely with what was described as left wrist inflammation.

Perhaps it’s a bit too soon to evaluate the Olson and Murphy deals before it’s known whether Tarnok, Cusick, and Estes can become full-time big-league players. For now, though, the Braves must like how both trades have worked out.

Murphy entered Monday with a .290 average, 11 homers, and 37 RBI to go with a .970 OPS. Olson was fourth in the NL with 16 homers, and the Braves had an NL-leading OPS of .798.

Murphy said he was not surprised to get traded, partly because he saw Langeliers start to emerge as one of the top prospects in the A’s organization before he made his MLB debut last August. Murphy was also eligible for arbitration for the first time, not an insignificant thing for the cost-conscious A’s. Murphy made $725,000 last season, per Spotrac, but is on a one-year, $4 million deal this season before a six-year, $73 million contract extension kicks in next year.

“Yeah, Shea looked awesome,” Murphy said. “When he came up and played so well, I saw the things he could do. I was like, ‘Oh, man, (the catching position is) in good hands if they do decide to send me out. So Shea performing as well as he did was, I’m sure, a factor.”

Oakland entered Monday’s series opener with the Braves on an 11-game losing streak, the club’s longest since the start of the 1996 season when it lost 12 in a row. Their 10-45 record was the second worst record after 55 games by any team since 1900, with the worst being the 9-43 mark compiled by the 1904 Senators, who had three games called with the score tied.

The A’s on Monday designated Jesús Aguilar for assignment. Aguilar was signed by the A’s to a one-year, $3 million deal, but became expendable with Ryan Noda emerging as the team’s everyday first baseman.

Asked if the Aguilar transaction can send a message to others in the A’s clubhouse, Kotsay said, “I think everyone in that locker room has come to acknowledge with where we’re at, nothing right now would surprise them in terms of moves or changes that would be made. At the same point, that group is continuing to come together, they’re continuing to search for ways though to get through this.”