Roy Robertson-Harris tore his Achilles during Giants Organized Team Activities yesterday, a blow that is expected to end his season before it began. The defensive lineman had been working with the first-string defense when the injury happened.

Robertson-Harris, 60, had signed a two-year, $9 million contract with the Giants a year ago and started all 17 games last season. Now the team loses a veteran who was supposed to help anchor a front already thinned by the trade of Dexter Lawrence last month.

Lawrence had been the Giants’ best defensive lineman, and his departure already changed the shape of the line. With Robertson-Harris sidelined, free agent additions DJ Reader and Shelby Harris become even more important, and the development of sixth-round rookie Bobby Jamison-Travis suddenly matters much more than it did a week ago.

The injury also deepens an offseason pattern the Giants cannot afford. Robertson-Harris is the second Giant to suffer a torn Achilles during offseason work, after rookie cornerback Thaddeus Dixon went down last week. Achilles tendon tears are almost always season-ending injuries, which means the Giants are now heading deeper into spring without two players who were expected to help.

That leaves the defense with fewer proven options and less margin for error before training camp even opens. The Giants can still piece together a front, but the loss of Robertson-Harris pushes more pressure onto players who were brought in to stabilize the unit, and onto a rookie whose role just became a lot bigger.