In a seven-season career, Sisler posted a 38–44 record with a 4.33 ERA in 247 appearances, including 29 saves, 12 complete games, one shutout and 656+1⁄3 innings.
[2] He tied for the AL league with a 1.000 fielding percentage by not committing a single error, although he had the sixth highest total of hit batsmen with seven.
He impressed his coaching staff during early spring practices, manager Mike "Pinky" Higgins commented that Sisler "looks good; he's more mature and shows more confidence".
[6] Although his ERA of 4.88 was considered high, it was due in large part to his loss against the Kansas City Athletics who scored six earned runs in just two innings.
[15] He recorded a save against the Baltimore Orioles on September 7, but closed the season with two consecutive losses against the Yankees, though he pitched well in the second game, giving up just three hits and two earned runs in eight innings.
[2] Sisler began the 1958 spring training in spectacular form, pitching a total of nine hitless innings and allowed just one baserunner in 28 batters faced; the last 27 in order.
[19] On May 2, he pitched his only career complete game shutout, a 6–0 victory against the Detroit Tigers and future Hall of Famer Jim Bunning, improving his record to 3–1 for the season.
[21] After what was considered a "disappointing" season, he did not impress with his first outing in spring training, giving up two hits and five bases on balls in just two innings of work.
[22] Lack of pitching depth was a noted weakness for the Red Sox entering the season, with unpredictable youth and with hopes that Sisler could regain his previous level of success.
Management decided that his performance along with a pitching staff that they considered inexperienced, Sisler and Ted Lepcio were traded to the Detroit Tigers on May 2 for starting pitcher Billy Hoeft.
[28] Continuing their rebound, the Tigers faced the Red Sox next, winning two of three, and Sisler pitched a scoreless one-inning relief appearance against his former team on May 6.
[31] The Tigers bullpen had won just nine games in 1959, but began 1960 with three straight victories, with Sisler pitching a scoreless two-inning appearance on April 22.
[2] The Senators received communication from several teams that were interested in Sisler, namely the Milwaukee Braves of the National League (NL) and the Athletics, but decided to trade their first pick in the expansion draft, Bobby Shantz, instead.
[35][36] New manager Mickey Vernon defined Sisler's role with the team before the season began, designating him as their top relief pitcher.
[37] Sisler felt slighted by the Tigers, having been left unprotected by the team, and had considered retiring from baseball, but ultimately decided to sign with the Senators.
[2][11] On September 16, the Senators agreed to send $75,000 ($764,700 current dollar adjustment) and a player to be named later to the Cincinnati Reds of the NL for pitcher Claude Osteen.
[2] The Reds were the NL champions in 1961, and with the addition of Sisler, Dave Hillman, and Moe Drabowsky to ensure stability to their pitching staff in 1962, the team's management had high hopes of a return to the World Series.
It was an unexpected decision considering that Sisler was former baseball player, but he did not feel that A. G. Edwards was benefitting, with the costs of running the team becoming more than originally agreed to by contract.
[50] Ichiro finished the season with 262 hits, and the Mariners extended an invitation for the entire Sisler family to attend the celebration at Safeco Field.