SAN FRANCISCO — The Giants announced on Friday afternoon that right-handed reliever José Buttó has a blood clot in his right arm and will undergo a procedure to remove it later today.

Buttó, who was placed on the 15-day injured list on Thursday, does not yet have a timeline to return. The team will provide an additional update on Saturday.

“At the very least, it’s peace of mind of what’s going on,” said manager Tony Vitello. “I don’t have enough history — I know a little bit about it — but it seems like this is something that’s occurred before he was with the Giants, or at least symptoms of it. So, maybe this has been building up for a while.”

Buttó, 28, was removed from Wednesday’s series finale against the San Diego Padres due to right arm fatigue. The right-hander faced eight batters and recorded one out, walking four batters and allowing four runs.

More concerning than the erratic command was the drop in velocity. Buttó’s fastball typically sits in the mid-90s, but he barely touched 90 mph by the end of Wednesday’s outing.

“He’s a very, very, very well-liked and well-respected guy. Everyone was concerned right away, and I think the fact it’s not worst-case scenario — or it could be worse — is good. Long story short, time will tell if it’s a decent layoff or an extended layoff,” Vitello said.

With Buttó hitting the injured list, right-hander Blade Tidwell was recalled from Triple-A Sacramento recorded the first save of his career, pitching three scoreless innings against his old team to secure the Giants’ 7-2 win.

“He wanted to be on that club to start the year — our club — as bad as you can possibly imagine,” Vitello said following Thursday’s win. “He’s a guy that you can tell when the emotions are there. He wears that intensity on his sleeve, and it didn’t work out. I don’t like the circumstances that caused it, but I do like the fact he stayed ready. He’s been throwing well, and he was hungry to get out there.”

Schmitt scratched, Encarnacion gets first start

First baseman Casey Schmitt was scratched from Friday’s starting lineup due to lower back tightness. Jerar Encarnacion took Schmitt’s place in the starting lineup, playing first base and hitting ninth.

Schmitt, 27, rebounded on Thursday evening from a tense Wednesday afternoon against the Padres, one in which third baseman Matt Chapman told him to “catch the (expletive) ball” after several misplays. Against the Mets, reached base four times in four plate appearances (three hits) and made a leaping snag to begin an unassisted double play.

Encarnacion, 28, has yet to start a game this season. He didn’t make his season debut until pinch-hitting for Patrick Bailey in the top of the seventh inning on Wednesday, grounding out in his lone plate appearance of the season.