PHOENIX -- The D-backs fine-tuned their 40-man roster Wednesday ahead of the 10 p.m. MT deadline to set the roster for next month's Rule 5 Draft.

Outfielder Ender Inciarte and right-handed pitcher Bo Schultz had their contracts selected from Triple-A Reno and were added to the 40-man roster.

In a corresponding move, the D-backs designated left-hander Tony Sipp for assignment, which removes him from the roster.

Players first signed at age 18 must be added to 40-man rosters within five seasons or they become eligible to be drafted by other organizations through the Rule 5 Draft process. Players signed at 19 years or older have to be protected within four seasons. Clubs pay $50,000 to select a player in the Major League phase of the Rule 5 Draft, slated to take place on Dec. 12. If that player doesn't stay on the 25-man roster for the full season, he must be offered back to his former team for $25,000.

In other words, an international player or high school draftee signed in 2009, assuming they were 18 or under as of June 5 of that year, must be protected. A college player taken in the 2010 Draft is in the same boat.

Inciarte, 23, was originally signed by the D-backs as a non-drafted free agent on May 25, 2008. The Venezuelan native has hit a combined .282 in six seasons in the Arizona system.

The Phillies selected Inciarte in the 2012 Rule 5 Draft, but returned him to the D-backs on April 4, 2013, having not appeared in a Major League game. Last year he spent most of the year with Double-A Mobile, where he hit .281 with 17 doubles, five homers, 25 RBIs and 43 stolen bases.

Schultz has had an interesting road to the 40-man roster. The 27-year-old graduated from Northwestern University and signed with the A's as a non-drafted free agent on June 22, 2008.

The A's turned him into a submarine-style pitcher, and after he was released by Oakland, he pitched in the independent American Association, where he went back to an over-the-top delivery. That caused his velocity to go up, and the D-backs signed him as a Minor League free agent on March 8, 2012.

Schultz pitched for Class A Visalia and Mobile in 2012 and received a Spring Training invite in 2013. This past season, he went a combined 5-6 with a 3.35 ERA in 37 games (16 starts) with Mobile and Triple-A Reno.

Schultz pitched for the Salt River Rafters in the Arizona Fall League this year.

Sipp was acquired last offseason in a three-team trade that included prospect Trevor Bauer and the D-backs had hoped he would be their left-handed specialist. Instead, Sipp struggled with his command, walking 22 batters in 37 2/3 innings and fell out of favor with the organization.

Sipp had been eligible for salary arbitration this year, and according to MLB Trade Rumors, he would have received $1.4 million through the process.

The D-backs 40-man roster is now full.