The 22-year-old, who has featured in all but two of the promoted side's 24 Bundesliga games this season, collapsed in the stadium roughly an hour after the match against Wolfsburg due to an acute stress reaction.
The Guinea international was immediately taken to the Uni-Klinik Leipzig hospital with the RBL club doctor for tests. He soon regained consciousness as his circulation returned to normal, but was kept in overnight as a precaution.
Following training on Sunday, coach Ralph Hasenhüttl gave a short update on his player's condition: "Naby is already feeling better. He did a lot of running in the game yesterday, which may be the reason for what happened."
Keita picked up his fifth yellow card of the season in the match and will therefore be suspended for the trip to SV Werder Bremen, allowing him further time to rest and fully recover.
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