HOUSTON -- Astros slugger Yordan Alvarez, the 2019 American League Rookie of the Year Award winner, said Friday he missed the team's Summer Camp and the first three weeks of the regular season while recovering from the coronavirus. Alvarez was activated from the injured list Friday, was in the lineup for the first time in 2020 against the Mariners and made a big impact right away.

Alvarez crushed a three-run homer into the Crawford Boxes off Seattle starter Nestor Cortes, who failed to make it out of the first inning after giving up seven runs. The ball left Alvarez's bat at 98.9 mph and traveled 343 feet, per Statcast.

Alvarez said he kept it quiet that he had the disease because he didn't want to worry his family in Cuba, though he told his parents.

"This has been a couple of difficult months for me," Alvarez said. "I know the team didn't say anything about it, but I did test positive for coronavirus. I had headaches and stuff like that, but thank God I'm feeling a lot better and I was able to get ramped up and feeling really good to be back with the team."

Alvarez, 23, said he tested positive two days before the start of Summer Camp in early July. His wife, Monica, also had the disease and was asymptomatic, but his young daughter, Mia, remained coronavirus-free. Alvarez isn't sure how he contracted the virus.

"Yeah, obviously, it's a scary situation for me, especially with my daughter, because I'm in contact with her every day," Alvarez said. "And I'm playing with her all the time, so it's a scary situation knowing that you're that close to your family and to have the virus is obviously scary at the outset."

Alvarez was placed on the injured list July 12 and began working out at the team's alternate training site in Corpus Christi, Texas, late last month. Astros manager Dusty Baker said the plan is to have Alvarez at designated hitter Friday and Saturday and probably keep him out of the lineup Sunday, when Michael Brantley is expected to DH.

"He said he was ready to go," Baker said. "I called him [Thursday] night and he said he had his bags packed and was ready to come back."

Alvarez figures to have a huge impact on Houston's lineup based on what he did as a rookie last year. He was called up in June and hit .313 with 27 homers and 78 RBIs in 87 games, becoming a unanimous choice for the AL Rookie of the Year Award. His 1.067 OPS is a Major League record by a rookie in a single season and the sixth highest by a player 22 years old or younger since 1900.

"He walked into the clubhouse and everybody was very happy," Baker said.

Alvarez said it was frustrating to feel good physically and not be able to play.

"You get a little stir crazy not going to the park and having been in quarantine all the time and more so, feeling physically good," Alvarez said. "I'm ready to go now."

To make room for Alvarez, right-hander Nivaldo Rodriguez was optioned to the team's alternate training site.