CHICAGO — Rookie outfielder Owen Caissie was diagnosed with a concussion and will be placed on the 7-day IL, the Cubs announced Sunday.

Kevin Alcántara was recalled from Triple-A Iowa in a corresponding move.

In the third inning of Saturday’s 5-4 loss to the Tampa Bay Rays, Caissie made a running catch on a fly ball hit to the right-center warning track before tripping over a sliding Pete Crow-Armstrong and crashing into the Wrigley Field ivy.

Caissie was slow to get up, remaining on one knee and taking his hat off while Crow-Armstrong checked on him. Replays showed the left side of Caissie’s head making contact with the ivy wall, but he remained in the game until the top of the sixth when Willi Castro replaced him in right.

“Owen has concussion symptoms,” Cubs manager Craig Counsell told reporters after the game. “He just kind of got gradually worse after running into the wall, and about 45 minutes later, he couldn’t continue.”

The 7-day IL is reserved specifically for players with concussion symptoms. A handful of major leaguers, including Los Angeles Angels catcher Logan O’Hoppe and Kansas City Royals pitcher Michael Wacha, recently have landed in protocol.

Caissie was recalled Saturday morning in a swap with Alcántara and went 0-for-2 with two strikeouts before the injury. In 26 MLB at-bats, the 23-year-old has five hits (.192) and four RBI, which includes his first big-league home run on Aug. 19 against the Milwaukee Brewers.

Alcántara, also 23, has one hit in his six MLB at-bats this year. He already was in the Cubs’ clubhouse Sunday morning before the roster move was announced, but he isn’t in the starting lineup for the rubber match against the Rays. Castro will pick up where he left off in right field as the Cubs gun for another series win.

The Cubs’ other option in right field, Seiya Suzuki, is out of the lineup for a third consecutive day while he deals with an illness. Cubs bench coach Ryan Flaherty said Suzuki was “still under the weather” for the series finale, and it hasn’t been decided if he will make the trip with the team to Pittsburgh immediately after the game Sunday.