The Tigers have a strong rotation, with Doug Fister, Max Scherzer, and Rick Porcello behind reigning AL Cy Young and MVP Justin Verlander. The club does have some concerns about the fifth spot though, and assistant GM Al Avila told James Schmehl of MLive.com that they'll remain on the lookout for pitching help during Spring Training.
“We’ll be looking at other pitchers in other camps throughout spring training to see if there’s anything that makes sense for us,” said Avila.
Avila did emphasize that the Tigers are comfortable with their in-house fifth starter candidates, namely Andy Oliver, Jacob Turner, Duane Below, and Adam Wilk. There aren't many clubs with starting pitching to spare, but John Lannan is said to be on the market and would make sense as a left-handed complement to Detroit's four right-handers. That's just my speculation, however.