GLENDALE, Ariz. -- The start of training camp isn't just about making the roster this season for some Arizona Cardinals. It's about playing for their next contracts.

There are 18 Cardinals who will be unrestricted free agents after this season, according to ESPN Stats & Information. Of those, about three or four may not make the 53-man roster in August.

The most high-profile of the upcoming free agents is quarterback Carson Palmer, whose contract voids five days after Super Bowl XLIX. Linebacker John Abraham, nose tackle Dan Williams, linebacker Sam Acho and long snapper Mike Leach will be up for renewal after 2014, as will tight ends Rob Housler and Jake Ballard. Then there are the players who signed one-year contracts during the offseason, including kicker Jay Feely, cornerback Antonio Cromartie, running back Jonathan Dwyer and linebacker Ernie Sims.

While training camp won't be a deciding factor for 2015 for some, they need to get on the roster in 2014 first. Housler will be among the upcoming UFAs who'll be closely watched during training camp. With the additions of John Carlson and Troy Niklas, and with Ballard already on the roster, Housler could be squeezed out.

Cromartie isn't just playing for a big contract in 2015 from the Cardinals, he'll be using this season as a tryout for the rest of the league.

Tackle Bradley Sowell, nose tackle Alameda Ta'amu, cornerback Teddy Williams and safety Curtis Taylor will be restricted free agents after 2014.

2015 unrestricted free agents:

OFFENSE:

QB Carson Palmer

RB Jonathan Dwyer

RB Jalen Parmele

TE Rob Housler

TE Jake Ballard

G Paul Fanaika

DEFENSE:

LB John Abraham

NT Dan Williams

LB Sam Acho

LB Keenan Clayton

LB Larry Foote

LB Ernie Sims

LB Marcus Benard

CB Antonio Cromartie

CB Bryan McCann

S Anthony Walters

SPECIAL TEAMS:

K Jay Feely

LS Mike Leach