The Lancaster Catholic grad was injured trying to make a diving catch during a preseason contest with the Rangers.
Jankowski was competing for a roster spot in a crowded outfield. But his defensive skills and speed made him a good fit as a fourth outfielder and pinch runner.
"Travis definitely brings some special ingredients . . . speed, the ability to defend," said Padres manager Andy Green, as reported by Bill Center of PadresMLBlogs.com. "Those are really strong attributes to him and we don’t have anyone else who is really the same level as him in that regard."
He also missed significant time in the 2017 season when a broken foot limited him to just 27 games with the Padres.
Last season, the lefty batter (he throws right handed) recorded career highs in batting (.259) and OPS (.678) and led the Padres with 24 stolen bases.
Jankowski was selected by the Padres out of Stony Brook in the first round of the 2012 draft and made his major league debut 2015.