The Giants reinstated Jackson (back) from the 15-day IL list Monday.

Jackson (back) is currently throwing from 90 feet, Maria I. Guardado of MLB.com reports.

The Giants placed Jackson on the 15-day injured list Friday with a lower-back strain, Maria I. Guardado of MLB.com reports.

Jackson suffered tightness in his lower back Thursday against San Diego and is being sent for an MRI, Shayna Rubin of the San Francisco Chronicle reports.

Jackson left in the seventh inning of Thursday's game against the Padres, Andrew Baggarly of The Athletic reports.

Jackson has allowed one run on one hit and one walk while striking out four over two Cactus League innings.

Jackson was activated from the paternity leave list Thursday.

Jackson was placed on the Paternity List prior to Monday's game against the Padres.

Jackson (1-2) took the loss Tuesday, surrendering four runs on three hits in two-thirds of an inning as the Giants fell 11-8 to the Cubs. He struck out two.

Jackson (1-1) allowed two runs (one earned) on a hit and two walks while striking out one in two-thirds of an inning to take the loss and a blown save Sunday versus the Athletics.