"There's reason for concern," Counsell said. Knebel will have a visit with team doctor William Raasch, according to the manager.
Knebel signed a one-year, $5.25 million contract in January after pitching well in the last month of the season and the postseason. In September, he gave up five hits in 16 1/3 innings and had 33 strikeouts with three walks. In nine postseason games, he held opposing hitters to a .090 average, with 14 strikeouts and three walks in 10 innings.