The injured third baseman took batting practice before Sunday's series finale against Cleveland.
"He's progressing nicely," Red Sox manager Bobby Valentine said. "He felt great [on Saturday]."
Youkilis fielded ground balls before Sunday's game, another first since his injury on April 28 vs. the White Sox. He is also throwing from 90 feet.
"That's another step up," Valentine said.
Youkilis is eligible to return from the 15-day disabled list on Monday, when Boston opens a two-game series against visiting Seattle. Sunday's game was the 14th contest Youkilis has missed since the injury.
Top prospect Will Middlebrooks has played well in Youkilis' absence, batting .282 with three home runs and 11 RBIs. Entering Sunday, Middlebrooks had eight extra-base hits in his first nine games, the most by a Red Sox player to begin a career since 1918.
Youkilis was batting .219 with two home runs and nine RBIs in 18 games before his injury.