That can-do attitude and talent was recognized by a lot of big league clubs and was part of the reason why he was selected in the first round of the 2014 draft by the Cleveland Indians out of high school with the 31 pick in the draft.
At the time, Sheffield was committed to play college baseball at Vanderbilt University for four years.
However, after being drafted, Sheffield changed his mind and decided to sign with the Indians became the first player to sign from the 2014 draft class.
Sheffield attended Tullahoma High School in Tullahoma, Tennessee and threw two no-hitters during his high school career.
During his senior year, Sheffield boasted an ERA of 0.34 and struck out 131 batters in 61, and two-thirds innings pitched. This performance earned him the 2013-2014 Gatorade National Baseball Player of the year award.
Once he signed his contract, Sheffield was sent to rookie ball by the Indians to play on their affiliate in the Arizona League.
Sheffield made his minor league debut on July 6, 2014, when he started a game for the Arizona League Indians.
In that performance, Sheffield went only 1, and a third allowed one run on three hits while picking up his first two professional strikeouts.
Sheffield made three more starts while appearing in eight games throughout the remainder of the season.
During his time in rookie ball, Sheffield posted an ERA of 4.79 in 20 and two-thirds innings while striking out 29 batters and only walking nine.
In his second year as a professional ballplayer, Sheffield was promoted to low A ball and played with the Lake County Captains in the Midwest League.
While with the Captains, Sheffield started all 26 games that he pitched in which resulted in him throwing a career-high 127 and two-thirds innings.
Despite the large workload, Sheffield was able to put up decent numbers with a 3.31 ERA and a 1.36 WHIP.
He also set a career high in strikeouts setting down 138 batters in his year with the Captains. Sheffield was able to accomplish this by picking up at least four strikeouts in 24 of 26 starts.
The southpaw averaged five innings per start with seven starts going six innings or longer and helped himself by walking less than three batters in 23 of his 26 starts.
Sheffield continued to climb the ladder in 2016, as his performance with the Lake County Captains the previous season earned him a promotion to high A ball.
The Indians assigned Sheffield to the Lynchburg Hillcats who play in the Carolina League.
Once he got there, Sheffield made an immediate impact going 7-5 in 19 starts with the Hillcats. He also had a 3.59 ERA and held batters to a .252 average against.
He still averaged around five innings per start with the Hillcats but showed improvement by keeping a lot of his statistics around the same level despite moving up a level.
Once on the Yankees Sheffield was sent to high A, where he joined the Tampa Yankees and made his first appearance in pinstripes on August 5.
During that outing, Sheffield went six innings, allowed two runs (one earned) and struck out 11 batters all while earning a win.
Sheffield went on to make four more starts for the Tampa Yankees where he put up another six-inning performance along with two, five-inning outings. He had an ERA of 1.73 and struck out 27 batters through the 26 innings he pitched at high A that year.
For his last start of the year, Sheffield was sent to double-A Trenton to pitch on September 2. Sheffield started that game for the Thunder and turned in 4 shutout innings while striking out nine batters.
Overall Sheffield had a 3.09 ERA over 125 and one-third innings in which he struck out 129 batters and held opponents to a .230 average against.
After finding success at three different levels in 2016, Sheffield received an invitation to big league spring training in 2017.
The Yankees did not give their top ten prospects a lot of playing time, but over the 3 and two-thirds innings that he did pitch, Sheffield only allowed one run.
The Yankees decided to send Sheffield back to double-A Trenton to see what he could do in extended time with the team.
The southpaw did not disappoint as he bumped his average startup to almost six innings per start with an ERA hovering a little over 3.00.
On July 5 Sheffield hit the first major road bump of his professional career thus far as he fell victim to an oblique injury which sidelined him until August 25 when he made his first rehab start with the Gulf Coast League Yankees.
In his rehab assignment, Sheffield went 0-1 over two games with a 1.93 ERA over 4 and two-thirds innings. He also struck out six batters and held them to a .235 BAA.
In an interview over the Arizona Fall League Sheffield said that he is a very competitive person and that the hardest part of the injury was not able to go out and help his teammates try to win games.
Finally, in September, Sheffield was able to make his return to the Trenton Thunder as he pitched three innings while giving up two runs in a loss.
Since the injury kept Sheffield out of the lineup for a little over a month, he only pitched 98 innings which put him short of the number of innings the Yankees wanted him to pitch.
Thus, the Yankees made the call to send Sheffield to the Arizona Fall League, so he could make up some of the time that he missed.
In the Fall League, Sheffield posted a 3.10 ERA in 20 and one-third innings of work. He also struck out 22 batters while holding opponents to a .192 average against.
Sheffield did not end the fall league on a high note. He left his final start in the second inning because he was hit in the leg with a comebacker.
Although he seemed to be OK, manager Jay Bell pulled him from the start for precautionary reasons.
Despite the injury, Sheffield still put up a 3.12 ERA in his 98 innings of work throughout the regular season with Trenton and the Gulf Coast Yankees. He also held batters to a .257 average while striking out 88 batters and putting up a WHIP of 1.35.
Sheffield was placed on the 2017 mid-season all-star team for the Eastern League (the league the Trenton Thunder play in) as well as the fall-star team in the Arizona Fall League. The lefty also earned Eastern League pitcher of the week honors back on the week of May 22-29.