PITTSBURGH -- Over the past two days, the Pirates have made steps toward finalizing their Opening Day roster.

On Sunday, the Pirates added catcher John Ryan Murphy to their 40-man roster. They also selected the contract of left-hander Robbie Erlin on Monday. Additionally, they placed right fielder Gregory Polanco on the injured list.

None of those moves should be considered a surprise. Murphy was bound to make the team as Jacob Stallings¡¯ backup catcher after Luke Maile underwent season-ending surgery on Friday to repair a fractured right index finger. Murphy joined the Pirates in Spring Training as a non-roster invitee on a Minor League contract, so the Bucs had to add him to their 40-man roster to put him on the 30-man active roster.

Similarly, Erlin signed a Minor League deal with Pittsburgh last offseason and came to camp as a non-roster invitee. The left-handed reliever¡¯s results have been uneven in Spring Training and Summer Camp, but the Pirates are confident he¡¯ll improve based on the work he¡¯s done since joining the organization. Assuming Steven Brault is used as a traditional or tandem starter, Erlin and Nik Turley are the only left-handed relief options remaining in Bucs camp.

¡°Right at the end of [Spring Training] 1.0, we started to see the effects of the plan that we were putting into place, the adjustments that we were doing,¡± manager Derek Shelton said. ¡°At the beginning of 2.0, there was a little bit [of a] step back, and I think we had to have some conversations about what we wanted him to do and how we wanted him to do it. In the last few outings, he¡¯s really executed that. Really happy with that and happy he¡¯s going to be part of the club.¡±

Shelton said the Pirates are ¡°still waiting¡± to finalize their roster. They¡¯ll have to select the contracts of a few other non-roster players who are expected to crack the 30-man squad, including left-hander Derek Holland -- who is in line to start the club¡¯s home opener -- as well as super-utility man Phillip Evans and Turley.

¡°We still have a few days left to make a decision,¡± Shelton said.

Polanco recently gave the team permission to announce that he tested positive for COVID-19 and has reported no injury, so he was presumably placed on the COVID-19-related injured list, not the 10-day IL. It¡¯s a key difference, because the COVID-19-related IL requires no minimum or maximum placement, meaning Polanco does not have to remain on the IL for 10 days if he is deemed healthy before then. Pittsburgh¡¯s starting right fielder can return as soon as he tests negative twice at least 24 hours apart and is cleared by doctors.

Major League Baseball has instituted a COVID-19 list this season, although clubs will not announce which players are placed on it due to privacy laws regarding individuals¡¯ health. Players may address their status if they wish, though they are not required to do so. Merely being placed on an injured list without further explanation is not confirmation that a player has tested positive for COVID-19. For example, potential exposure to a person who has the virus can be sufficient cause.

Pirates general manager Ben Cherington said during the AT&T SportsNet Pittsburgh telecast of Saturday¡¯s exhibition game at PNC Park that Polanco is asymptomatic and ¡°feeling great¡± with ¡°no issues at all.¡± Since going on the injured list, Polanco has posted videos on his Instagram account in which he is working out inside his home, doing squats and swings with a kettlebell and various exercises with resistance bands.

¡°He's just going to have to be patient and get through the protocol,¡± Cherington said on Saturday¡¯s telecast, ¡°and he'll be back before we know it.¡±