Sources: Mets, Yankees attended David Robertson's throwing session

Red Sox chief baseball officer Craig Breslow was also in attendance to watch Robertson, who he spent time with during his days with the Chicago Cubs. Robertson pitched for the Cubs in 2022 while Breslow served as assistant GM for Chicago.

Robertson, 40, is self represented and has not pitched with a team all season. After declining a mutual option with the Texas Rangers, Robertson has gone unsigned to this date. However, the right-hander is coming off a campaign with the Rangers, where he posted a 3.00 ERA with 99 strikeouts across 72 innings in 2024.

Robertson pitched for the Mets back in 2023, in which he took over as the team's closer after Edwin Diaz went down with a torn patellar tendon in his knee during the World Baseball Classic. As a member of the Mets, Robertson produced a 2.05 ERA and 14 saves across 44 innings before being dealt to the Miami Marlins at the MLB Trade Deadline.

Now, the Mets and Robertson could potentially reunite with New York in need of relief help ahead of the Trade Deadline. The Mets lost left-handers' A.J. Minter (lat) and Danny Young (Tommy John surgery) to season-ending injuries earlier in the year. While Robertson is a right-hander, he has excellent splits against left-handed batters in his career, holding them to just a .187 average.

The Mets will surely look to trade for bullpen arms at the deadline, but they could stand to bring in multiple relievers, which is where Robertson, a free agent, makes sense. The Mets have been showing interest in Robertson as of late and were one of the teams to attend his recent throwing session.