Underwhelming debut took some luster off Giolito's bright star

As we transition into offseason mode here, we're reviewing each significant player on the Nationals roster. We continue today with Lucas Giolito, the top pitching prospect who underwhelmed in limited action.

PLAYER REVIEW: LUCAS GIOLITO

Age on opening day 2017: 22

How acquired: First-round pick, 2012 draft

MLB service time: 39 days

2016 salary: $507,500

Contract status: Under club control in 2017, arbitration-eligible in 2020, free agent in 2023.

2016 stats: 0-1, 6.75 ERA, 6 G, 4 GS, 0 CG, 21.1 IP, 26 H, 18 R, 16 ER, 7 HR, 12 BB, 11 SO, 1 HBP, 1.781 WHIP, -0.5 WAR

Quotable: "I think it was a great learning experience for him. You're talking about a young, front-end prospect. Now you transfer from prospect in Major League Baseball to major league pitcher. There's a lot of trials and tribulations that come along with it. We've got great confidence in him. He's going to be a big part of us for a long time." - Mike Rizzo on Lucas Giolito

2016 analysis: Lucas Giolito's major league debut was anticipated for some time, and there was no way to know for sure when it would occur, given the Nationals' attempts to bring their top prospect along slowly while also recognizing their needs at the big league level.

The debut came on June 28, earlier than some expected but necessary when Stephen Strasburg was dealing with a strained back. Giolito's performance was about as encouraging as it can get; he tossed four scoreless innings against the Mets, allowing just one hit, before a rain delay abruptly ended his night.

Giolito never did look the same after that, though. He averaged only four innings per start, never reaching the sixth. He never struck out more than four batters in an outing. He wound up with more walks than strikeouts. And his fastball velocity, expected to be in the mid-to-high 90s, averaged only 93.3 mph and topped out at 95.8 mph.

Given several opportunities to seize an open spot in the rotation, Giolito never did take the ball and run with it. He wound up making a couple of relief appearances in September and wasn't part of the Nationals' postseason staff.

2017 outlook: The Nationals would have loved for Giolito to show enough this season to warrant a guaranteed spot in next season's opening day rotation, but that didn't come close to happening. If anything, the young right-hander was pretty underwhelming, given the lofty pedigree he brought with him to D.C.

With all the regular members of the Nats rotation under contract and expected to return healthy in 2017, there almost certainly won't be a spot for Giolito in April. That could ultimately prove best for him, giving him a chance to hone his craft more in a less-pressurized situation at Triple-A Syracuse (where he only has made seven career starts).

With a fresh arm, the Nationals hope to see Giolito's velocity return next year. And they hope he proves himself ready for the challenge when called upon at some point during the course of the season. Then they'll start to get a better idea whether their prized prospect really is going to be a key part of this staff in the near future or whether the jury is still out.