The 25-year-old first baseman has adjusted, and the Padres are seeing positive results.
Alonso doubled in a run during a 2-for-4 day in the Padres' 6-2 loss to the Rockies on Wednesday, giving him hits in 12 of the past 13 games, batting .400 (20-for-50) with eight two-baggers over the stretch. He finished the day hitting .292 and had a seven-game hitting streak.
"We've seen a guy that has settled in," Black said before the game. "When you're part of a significant trade, I think there are some internal pressures [you] put on yourself. When we get new jobs, we want to impress. You're not quite yourself, because you're trying to really make an impression. I think that was the case with Yonder."
Alonso joined the Padres along with hurlers Edinson Volquez and Brad Boxberger and catcher Yasmani Grandal in a December trade with the Reds, who received right-hander Mat Latos.
Black said Alonso's progress is reflected in his overall game.
"Even a couple of the errors he made early in the year were made out of haste and trying to make plays, really trying to do some things defensively, because he wasn't doing them offensively," Black said. "He's relaxed. He's swinging the bat like all our scouts thought he would. He's using the whole field and he's hitting line drives."
Alonso agreed he's more relaxed.
"I think the beginning of the season was a little bit fast," Alonso said. "It was a little hectic at times, but lately, I've been slowing the game down. I've been trying to focus better. I focus a lot better, and my preparation has been a little better. And just trusting myself."
Four of Alonso's eight RBIs arrived in his last three games.
"It shows the team is grinding and getting on base and getting in scoring position," Alonso said. "It's always a plus when it's a whole team thing, so it's been good."