The Toronto Blue Jays placed left-hander Hyun Jin Ryu on the 10-day injured list Sunday with neck tightness.
General manager Ross Atkins told reporters he is hopeful Ryu misses just one start. Atkins said Ryu woke up with the tight neck on Saturday, the day after his last start, against the Minnesota Twins, when he took the loss after giving up five earned runs and two home runs in just two innings pitched.
Ryu (13-9) is tied for the team lead in victories.
The Blue Jays enter Sunday's games with a half-game lead over the New York Yankees for the second wild-card spot.