PITTSBURGH -- The Pirates must make a few tough decisions -- and two easy ones -- before Tuesday's deadline to protect eligible players from the upcoming Rule 5 Draft.
Tuesday is the annual deadline for Major League clubs to decide which Minor Leaguers are worthy of spots on 40-man rosters and which young players will be left unprotected in the Rule 5 Draft. Eligible players left off the 40-man roster can be taken in the Rule 5 Draft, which will take place on Dec. 13 at the Winter Meetings in Las Vegas.
Players who signed with their current team at age 18 or younger and have played professionally for at least five years are eligible to be selected. So are players who signed at 19 or older and have at least four years of professional experience. For example: Kevin Newman and Kevin Kramer, both selected out of college in the 2015 MLB Draft, would have been eligible if the Pirates hadn't already put them on the roster.
The Bucs must evaluate eligible prospects by considering their short-term impact, long-term upside and appeal to other clubs. The club needs to protect the right players while also understanding the value of a 40-man roster spot.
Pittsburgh has 37 players on its 40-man roster, giving general manager Neal Huntington and the front office little wiggle room. The Pirates won't necessarily fill their roster, instead keeping a spot or two open for additional acquisitions, and it is generally considered unwise to protect too many players.
The easy calls
Right-hander Mitch Keller and shortstop Cole Tucker will certainly be added to the roster before Tuesday's deadline.
Keller is ranked as the Pirates' top prospect and No. 16 overall by MLB Pipeline, and he could make his big league debut as soon as next summer. Keller, 22, was a second-round pick in the 2014 MLB Draft, and he cruised through the Minors. He struggled in his first taste of Triple-A, posting a 4.82 ERA in 10 starts, but there is little doubt that he possesses the necessary athleticism, stuff and makeup to help the Bucs' rotation soon.

Tucker, 22, just completed an excellent campaign in the Arizona Fall League with a .370 average and an .899 OPS. The Pirates' first-round pick in the 2014 MLB Draft, Tucker is ticketed for Triple-A next season after hitting .259 with a .689 OPS and 35 steals in Double-A. The No. 5 prospect could make his MLB debut late next season, and it wouldn't be a surprise to see him compete for the starting shortstop job in 2020.

The tough decisions
There are dozens of eligible prospects in the Pirates' system, but three of them have particularly compelling cases to crack the roster.
Jason Martin, OF: Martin wasn't selected despite being left unprotected by the Astros in last year's Rule 5 Draft, but he is now a step closer to the Majors in a new organization. The 23-year-old, acquired in the Gerrit Cole trade, dominated in Double-A, but he faltered in Indianapolis. Martin hit just .211 with a .589 OPS in Triple-A, but he held his own in center field most of the season. The Pirates lack high-upside, upper-level outfield depth, so it would make sense for them to protect Martin.
J.T. Brubaker, RHP: Brubaker was the Pirates' Minor League Pitcher of the Year last season, an indication of how much they like him. A sixth-round pick in the 2015 MLB Draft, Brubaker posted a 3.10 ERA over 22 starts in Triple-A this year after a quick stop in Double-A. That success would seemingly make Brubaker part of Pittsburgh's near-ready pitching depth and therefore a logical candidate to be put on the roster.

Brandon Waddell, LHP: This might be the Pirates' most difficult debate. The No. 24 prospect has put up consistently solid numbers since being selected in the fifth round of the 2015 MLB Draft. After reaching Triple-A last season, he's on the brink of the Majors at 24 years old. He likely projects to be a back-end starter without overpowering stuff, not the kind of player clubs typically claim in the Rule 5 Draft, but someone could stash him in the bullpen. The Pirates may add him due to the dearth of lefties on their roster, or they could take a calculated risk and leave him unprotected.