HOUSTON -- New York Mets right-hander Paul Blackburn will begin the season on the 15-day injured list with right knee inflammation, team president of baseball operations David Stearns announced Wednesday during the team's workout at Daikin Park.

Stearns also said that right-handed relievers Max Kranick and Huascar Brazoban and catcher Hayden Senger have made Mets' opening day roster.

After the workout, infielder Luisangel Acuna was informed that he had made the roster, a source confirmed to ESPN, rounding out the Mets' projected 26-man roster. The club has until noon Thursday to finalize the group before opening the season against the Houston Astros.

Blackburn was slated to pitch out of the bullpen to begin the season. Stearns said Blackburn reported knee soreness in the days after his last spring outing. He received an injection for the discomfort and will be shut down for seven to 10 days. Stearns added that the injury isn't believed to be serious, and Blackburn is expected to return before the end of April.

Acuña and outfielder Alexander Canario were the only two healthy position players who attended the Mets' workout Wednesday and hadn't been told whether they made the roster.

With Acuña on the roster, barring a last-second development, Canario won't make the team. Canario, who is out of options, would be exposed to waivers if he isn't put on the roster. The Mets already have six outfielders on their projected roster.

"It's really just ensuring we stay open to what might be out there," Stearns said during the team's workout. "This is a highly active time of year as players are on waivers, players have assignment clauses, players have upward mobility clauses, players take their outs and become free agents, players become available at the last minute before rosters are submitted. And the last thing we want to do is tell a player that they are on the opening day roster and then have to walk that back before rosters are due."

Acuña, the younger brother of former Braves MVP Ronald Acuna Jr., is a former top prospect who impressed during his first major-league stint at the end of last season. The 23-year-old Venezuelan batted .308 with a .966 OPS and three home runs in 14 regular season games as the Mets fought for a playoff spot down the stretch. He mostly played shortstop in place of the injured Francisco Lindor, and has played second base and center field as a pro. This spring, he spent time at third base for the first time.

Kranick, a 27-year-old lifelong Mets fan from Pennsylvania, hasn't pitched in the majors since appearing in two games for the Pittsburgh Pirates in 2022. Brazoban, 35, was traded to the Mets last summer and posted a 5.14 ERA in 19 appearances with the team.

Senger, at 27 years old, has never been on a major-league roster, having spent the last seven seasons in the minors. The opportunity opened for him opened when starting catcher Francisco Alvarez fractured his left hand earlier this month. Senger was a 24th-round pick in 2018 who has spent the last two winters working at a Whole Foods in the Nashville area while his wife, Ryann, worked as a physician's assistant to help keep his dream alive.

"I gotta give a shoutout to my wife," Senger said. "She has worked for a lot of years to support me through this and it kind of made it all worth it now that I get to say I'm a Major League Baseball player."