Vernon Davis has added intrigue to the question of whether he will show up for the San Francisco 49ers' mandatory minicamp, which starts Tuesday.

Vernon Davis shone some light on his thoughts about a holdout in a Sports Illustrated column posted Monday. AP Photo/Tony Avelar

Writing a guest column for Sports Illustrated's MMQB, Davis detailed why he has stayed away from the 49ers' voluntary sessions and even mentioned the word "holdout." He can't officially become a holdout until he misses a mandatory session. The 49ers can start fining him Tuesday if he is not present.

"In 2010 I signed a five-year, $37 million contract extension with $23 million guaranteed. It was the biggest contract for a tight end in league history," Davis wrote. "Four years later, and I'm playing at a higher level than I was then, which brings me to why I'm holding out. It's all about getting paid what you deserve. It's not that complicated. I want the 49ers to win the Super Bowl, and I want to be on the field this summer working towards that goal, but I have to worry about my future first."

Davis' stance on Monday appears to contradict what he's said in the past. On Thursday, he told a San Francisco radio station: "You know what? I plan on being there. I plan on being there."

And on June 5, Davis told ESPN.com: "If it's mandatory, I think I should be there. My foot could get stuck in the grass, and I may not be able to get out ... but if it's mandatory, I think I should be there."

After his latest words, it appears Davis, at the very least, is wavering on his decision.

One Niner who isn't wavering is guard Alex Boone. According to a league source, Boone will not be at the minicamp because he wants a new contract and is willing to start his holdout. He has not been at voluntary offseason sessions. His contract runs out in 2015.