During the next two seasons, Palmer struggled with arm injuries. He had injured his arm in 1966 while using a paint roller in his new house in Baltimore. Cortisone injections allowed him to pitch through the rest of the season and the Worlds Series, but in 1967, his arm continued to feel heavy. He threw a one-hit game against the New York Yankees on May 12 but was sent to the minor leagues after a poor start against the Boston Red Sox five days later. While trying to make it back with the Rochester Red Wings in Niagara Falls, New York that Palmer surrendered the only grand slam in his entire professional career which was hit by the Buffalo Bisons' Johnny Bench. He only pitched three more games for the Orioles in 1967. In 1968, he was limited to 10 minor league games, with no appearances for the Orioles. The outlook on his career was so bleak, Palmer considered quitting baseball to attend college or trying to be a position player. He had been placed on waivers in September 1968 and was left unprotected for the Kansas City Royals and Seattle Pilots in the expansion draft one month later, but was not claimed. After he pitched for an Instructional League team, the Orioles sent him to pitch for the Santurce Crabbers in the Puerto Rican Winter League. Before he left for Santurce, however, Palmer attended a Baltimore Bullets game and sat next to Marv Foxxman, a pharmaceutical representative who suggested he try Indocin. In Santurce, Palmer's arm stopped hurting, and his fastball began hitting 95 mph again. "It was a miracle as far as I was concerned," said Palmer.