Erasmo fué descubierto a la edad de 14 años por un antiguo coach que estaba entregando equipo a jóvenes necesitados en Nicaragua. Ese hombre ayudó a Ramírez a ser aceptado en una academia de beisbol en El Salvador, lejos de su familia, donde fue entrenado y firmado por los Marineros. Una sugerencia que el recibió de la academia, fué que dejara de sonreir mientras el estaba lanzando, porque eso se mal interpretaba por los bateadores opositores, ya que el siempre estaba sonriendo a todas horas.

Erasmo Ramirez ha tirado 7,497 lanzamientos en los cuales han sido rastreados por el sistema PITCHf/x entre 2010 y 2017, incluyendo lanzamientos en la temporada regular de la MLB y el entrenamiento primaveral. En 2017, el ha dependido primariamente en su Excavador “Sinker” (92mph), tambien mezclando en su Deslizador “Slider” (85mph), Cambio “Change” (83mph), Cortador “Cutter” (90mph) y su Bola Rápida de Cuatro “Fourseam Fastball” (93mph).

2016
Logró liderar el equipo con 64 apariciones (1 comienzo) en su primera temporada completa como relevista. Sus 85 entradas lanzadas lideró la Liga Americana, posicionándolo 2do. en las mayores después del lanzador zurdo (LH) de los Padres, Brad Hand (89.1) y fué el más logrado por un lanzador de los Rays desde el lanzador zurdo (LH)  J.P. Howell (89.1) enn 2008.
His 11 losses as a reliever were the most by a major leaguer since LAA Scot Shields (11) in 2005 and set a club record, passing RH Brad Boxberger (10) in 2015.
His 7 wins included 6 in relief, one shy of the club record for a reliever (last J.P. Howell in 2009). His 17 decisions in relief were the most by a major league reliever since 2010.
Began the season 4-0 over his first 6 apps (1 start), the first pitcher in club history with 4 wins through the team’s first 15 games.
Made his only start on April 16 vs. CWS, a 7-2 Rays win…his line: W, 3 H, 0 R, 0 BB, 4 SO.
Recorded his first career save on Aug 9 at TOR, retiring all 9 BF on 27 pitches…marked the fewest pitches for a 3-inning save (or longer) in club history…was the third pitcher in club history to record a save on 3 perfect innings.

2015
In his first season with the Rays (and first full season in the majors) set career highs with 27 starts, 163.1 IP and 11 wins…his 11 victories finished one shy of Chris Archer for the team lead and tied Matt Garza (11-9 in 2008) for most by a Rays pitcher the season after he was acquired via trade.
From April 19 through the end of the season he was one of the best pitchers in the AL, ranking among league leaders with a 3.02 ERA (4th), .223 opp avg. (4th), .274 opp OBP (3rd), .344 opp SLG (4th) and 1.04 WHIP (2nd).
His 11-6 record (.647) tied for the 10th-best winning pct. in the AL.
Became the first Nicaraguan to beat the Yankees twice in the same season, with a 6-1 win on May 14 at home (5-IP, 1-H, 0-R) and an 8-1 victory on July 5 at Yankee Stadium (6-IP, 3-H, 1-R).
Became the sixth pitcher in Rays history to carry a no-hitter into the 8th inning, first since Alex Cobb on Sep 11, 2014 at NYY (7.1 hitless)…his line: ND, 7.2 IP, 1 H, 0 R, 2 BB, 6 SO, 98 pitches, 62 strikes.

Acquired from Seattle a week before Opening Day for LH Mike Montgomery…came to Mariners camp out of options. Erasmo went 1-2 with a 6.23 ERA (13-IP, 9-ER) in 5 apps, 4 starts in Mariners camp.

2014
Went 1-6 with a 5.26 ERA (44 ER, 75.1 IP) in 17 G/14 GS… Ended the season with a 6-game losing streak…after winning season debut, went 0-6,5.53 over final 16 appearances.
Recorded career-high scoreless streak of 19.2 innings June 3-24.

2013
Went 5-3 with a 4.98 ERA (40 ER, 72.1 IP) in 14 G/13 GS over two stints with the Mariners. Made his first start of the season at the Major League level July 11 vs. the Red Sox…recorded a ND in Mariners 7-8 loss in 10 innings (4.2,6,7,7,4,4,HR). Career-high 4-game win streak July 23-Aug. 13, going 4-0 with a 5.84 ERA (16 ER, 24.2 IP) over 5 G/4 GS.
Started the season on the minor league DL (April 11-May 28) with right triceps tendinitis. One of four Nicaraguan-born players to appear in MLB during the season…also: Everth Cabrera – SD, Wilton Lopez – COL, J.C. Ramirez – PHI. Pitched for Cardenales de Lara in the Venezuelan Winter League (3-1, 2.86 ERA, 6 GS).

2012
Went 1-3 with a 3.36 ERA (22 ER, 59.0 IP) in 16 G/8 GS over two stints with the Mariners.
Struck out career-high 10 batters June 25 vs. Oakland (L#2; 8.0,3,1,1,1,10)…at the time became the 8th Mariners rookie (17th time) to record 10 strikeouts in a game…at 22 years, 54 days, was 4th-youngest Mariner to record a double-digit strikeout performance.
Recorded his first Major League win Sept. 11 at Toronto (7.0,6,2,2,1,6).
Made first Major League start June 14 vs. San Diego, suffering the loss (5.0,8,6,5,1,3).
Debutó en Grandes Ligas con Los Marineros de Seattle el 9 de abríl del 2012, contra Los Rangers de Texas durante 3 inning, permitó 2 imparables y 1 carrera limpia, dio 1 base por bola y ponchó a 3. Tenía 21 años y 343 días de edad, siendo el lanzador más joven de Seattle al momento de su debut.

2011
Split season between AA Jackson and AAA Tacoma, going 10-8 with a 4.83 ERA (82 ER, 152.2 IP), while walking 41 and striking out 116 in 26 starts. Listed by Baseball America as the Mariners No. 13 prospect.

2010
Named Clinton’s Pitcher of the Year by the Mariners … ranked 4th among all Mariners farmhands with a 2.97 ERA…named to the MWL Midseason and Post-Season All-Star Team.

2009
Spent season in the Venezuelan Summer League, leading the league in ERA, wins, strikeouts and innings pitched … named Seattle Mariners Minor League Pitcher of the Year and the VSL Most Valuable Pitcher … also named VSL Most Valuable Player … went 11-1 with 0.51 ERA in 14 games (13 GS) … limited opponents to .174 (54×310) batting average…season-high 7-game win streak (7-0, 0.71 ERA, 4 ER, 51.0 IP), June 23-Aug. 4 … struck out 10 batters in back-to-back starts, May 25 and 31…did not allow an earned run in 26.0 consecutive innings over 5 starts, June 12-26.

2008
Made professional debut in the Venezuelan Summer League, going 4-1 with a 2.86 ERA (20 ER, 63.0 IP) in 13 games, 11 starts … allowed 2 or less earned runs in 8 of 11 starts.