MESA, Ariz. — Commissioner Rob Manfred was in Oakland last month and visited potential A’s stadium sites, team president Dave Kaval told The Chronicle on Friday.

“The commissioner came to look at our new offices and I think he was impressed, and he also looked at the sites for a ballpark,” Kaval said at the A’s minor-league complex. “It was nice to give him a good tour.”

According to sources, the main focus of Manfred’s visit was Howard Terminal, the waterfront area near Jack London Square that is minutes away from the team’s new offices and is one of three areas the A’s have pinpointed during their stadium search.

Manfred has visited the A’s preferred site near Laney College previously, and of course he’s familiar with the third option, the Coliseum. Manfred is in regular contact with Oakland Mayor Libby Schaaf — a longtime supporter of the Howard Terminal site — and as Kaval noted, MLB has extensive experience with helping to troubleshoot stadium development issues.

“More than anything, we want to make sure everyone knows our efforts in Oakland to build a privately financed stadium and what it will take to make that happen — working with all the key stakeholders: the league, the city, maybe the port, the (Coliseum Joint Powers Authority),” Kaval said. “The league has a lot of expertise when it comes to ballpark development and situations that have worked and not worked, and relying on that I think is important.”

In trying to evaluate the transportation issues, for example, at Howard Terminal — which is a 20-minute walk from the nearest BART station — MLB can point to past workarounds in Cleveland, Baltimore and Toronto, Kaval said, adding, “That’s really where the league can be a best-practice clearinghouse.”

The A’s remain “100 percent focused on Oakland,” Kaval reiterated. “Obviously, we had a setback with our preferred site, but we’re still looking at all three sites and working with our partners and various stakeholders with a timeline for a 2023 opening, and we’re still on track with that path.”

Minor-leaguer starts fund: A’s pitching prospect Jesus Luzardo, obtained in the Sean Doolittle deal with Washington last year, graduated from Douglas High School in Parkland, Fla, two years ago. Friday, the left-hander created a memorial fund for the family of murdered athletic director Chris Hixon.

”Chris played a huge role in supporting my dreams of becoming a professional baseball player and his loss will be felt by everyone in the Douglas community,” Luzardo said in a post with the fund.

To donate, go to https://www.youcaring.com/familiesofthedouglashighschoolvictims-1101050#mlb-oakland.