The Red Sox would go on to lose the game 6 to 2. For the rest of September, Bolling put up typical numbers for a shortstop of the era. He hit .222 with a lone home run on September 16 and three runs batted in for only 36 at bats.  1953 was the first full Major League season for Bolling. He competed with veteran Lipon for the starting role at shortstop which was eventually won by Bolling when the Red Sox sold Lipon to the St Louis Browns on September 8. On April 16, opening day for the Red Sox against the Philadelphia Athletics, Milt started at shortstop and got off to a red-hot start, going 4 for 5 with a double and one run batted in en route to an 11–6 victory. Milt finished April with a strong .293 average, but struggled in May and June with monthly batting averages of .215 and .229. In July, Bolling's bat got white hot as he hit .380 in 71 at bats. He eventually tapered off but put up a respectable .263 batting average with five home runs and 28 RBIs in 109 games as the Sox shortstop. He was sixth in the American League for sacrifice hits with 13.  1954 was more of the same for Bolling, except this time he led the American League in errors committed with 33. However, he was fourth with assists at shortstop, and first with his range factor. Milt put down 13 more sacrifice hits, good enough for fourth in the league. Bolling was third in doubles among all AL shortstops with 20. His hitting got off to a slow start and he never truly recovered, batting just .249 with six home runs and 36 RBIs. On March 23, 1955, Milt had a career-threatening injury when he broke his left elbow in a Spring training game against the St. Louis Cardinals after he had already won the starting role at shortstop for the season. He was expected to return after six weeks, but ended up playing in only six games for the entire season. By the time Bolling got a clean bill of health, he had lost his starting job to Don Buddin for the 1956 season. Milt was a rarely used pinch hitter until he started seeing some starts at the tail end of the season in August and September. He could only muster a .212 batting average to go with 3 home runs and 8 RBI in just 45 games. After playing just one game into the season for the Red Sox off the bench, on April 29, 1957, the Red Sox traded Bolling along with Russ Kemmerer and Faye Throneberry to the Washington Senators for Bob Chakales and Dean Stone.