OAKLAND — Jharel Cotton’s 2017 has officially reached its end as the Oakland A’s are holding him out of his scheduled start on Friday due to concerns about his elbow.

Cotton’s MRI came back clean, but the A’s don’t want to take any chances, instead planning to have the right-hander throw an extended bullpen in Texas over the weekend.

“He’s healthy and we want to make sure he stays healthy,” manager Bob Melvin said. “It doesn’t seem like it’s worth the risk of going out there this late in the season, throwing 100 pitches — potentially getting a little bit sore again.”

Raul Alcantara will start in his place. Cotton joins Matt Olson (hamstring) and Boog Powell (knee) as A’s who are out for the season, while Chad Pinder (concussion) is holding out hope he’ll return for the final game or two.

Olson earns a daily spot

Olson, the A’s 24-home run rookie, has seized his opportunity in an unparalleled manner.

“I haven’t been around anybody who’s taken advantage of it in the fashion that he has,” Melvin marveled.

Thanks to his power and steady glove work, Olson heads into 2018 as the guy at first.

“Well, I mean, he’s not going to play 162 games,” Melvin conceded. “If he does get some days off, it will probably be against left-handed pitching, but I think he’s done enough to show, that yes, we consider him an everyday first baseman.”