The Padres needed to free up a spot on their 40-man roster to promote Tyler Wade on Friday which forced them to move Waldron to the 60-day IL. The expectation had originally been that the knuckleballer could be ready to return from his oblique injury before the end of April, but now he won’t be eligible to return until the end of May at the earliest.

Waldron was expected to open the year in either San Diego’s starting rotation or bullpen prior to suffering an oblique strain earlier this month. Barring any setbacks, he should be an option before the end of April.

Waldron’s absence opens up a spot in San Diego’s season-opening pitching mix. The 28-year-old righty suffered the injury while warming up in the bullpen on Friday evening. He’ll be re-evaluated this weekend, but isn’t expected to be ready in time for Opening Day. He vying for the final spot in the Padres’ rotation along with Kyle Hart and Stephen Kolek. We’ll give the slight edge to Kolek at the moment since he’s tossed five scoreless frames this spring, while Hart has yet to appear in a Cactus League game.

Waldron gave up two hits, issued a pair of walks and only notched one strikeout. The 28-year-old doesn’t have a clear path to a spot in San Diego’s season-opening rotation following the offseason additions of Nick Pivetta and Kyle Hart, which means he’ll likely open the year as a multi-inning relief option or head back to Triple-A El Paso.