The Blue Jays closer fell victim to either food poisoning or a virus during a trip to the Dominican Republic.
"It got me pretty good the other night," said Janssen, still looking a little pale. "I'm feeling a little better today. Still a little weak."
The six-foot four 205-pound Janssen required IVs after losing seven-plus pounds "in a matter of about 10 hours."
"So just go ahead and think what that was like," he said wryly. "But I'm starting to get down a little bit more food."
Aaron Loup pitched the ninth in place of Janssen as the Jays downed the Texas Rangers 4-1 Saturday.
"It eats you up when you can't help and compete. Obviously Loup did a great job (today) and we were able to get the win. But I think we need all hands on deck to try and make this second half special," said Janssen, who converted 14 of 16 save opportunities in the first half of the season.
"I hope to be in the middle of it and be a big part of it."Suggest a correction