Wells, 26, took a glancing blow off the tip of his nose as he tried to back away from Morrow's high-and-tight pitch. He went down momentarily before being helped off the field by trainers with a towel on his nose.
Manager Eric Wedge said X-rays on Wells were negative and his status is day to day, while Wells said he hoped to be ready to play on Friday in the series opener against Tampa Bay.
"He should be OK," Wedge said. "Anytime you get up there it's scary. But we dodged a bullet."
Morrow was throwing 98 mph gas most of the night in his first start at Safeco Field since being traded by Seattle after the 2009 season. He had runners on first and second in the sixth inning with two out when his first pitch to Wells sailed up and in on the right-hander.
"It just felt like my nose fell off, pretty much," Wells said, cotton stuffed in his swollen nose. "I couldn't see, which was scary. My eyes got all watered up and I couldn't see what was going on.
"I felt like it squared me up right in the face. But watching the replay, I kind of got out of the way. But it was really scary more than anything, just coming right at my face."
Wells said he had a headache and "my nose feels humongous, but I think I'll be all right."
Wedge said he thought Morrow was tiring and that's why the pitch got away from him. Wells also said he didn't think it was on purpose.
"He stands all the way on the side of the rubber and when you pick it up, you have less time than with most pitchers," Wells said. "I saw the replay and the pitch wasn't even close to the strike zone. It was coming right at my head. It's not like he was trying to throw it deliberately there, but that one definitely got away from him."
Morrow, 26, said he was just glad Wells wasn't hurt.
"I couldn't tell live where it exactly got him and the way he reacted I was worried about it," Morrow said. "But I heard it just tipped his nose and the X-rays are negative, so I'm glad he's all right."
Wells' locker in the Mariners clubhouse is adjacent to first baseman Justin Smoak, who is sporting a black eye and broken nose after going on the disabled list following a wicked bad hop grounder that caught him flush in the face last week.
Wells figures that should be warning enough for rookie outfielder Trayvon Robinson, who has the next locker down from the two. And, no, he's not sure who is going to look worse between he and Smoak in the coming days.
"I don't know," Wells said with a smile. "He's starting to heal, so he's getting uglier day by day. But I'll probably look uglier [Thursday]. I need to get my locker moved, though. Trayvon better be heads up next time."