Ackley, the No. 2 pick in the 2009 amateur draft, batted .148 with no homers and four RBI in 28 games last season. He tore the labrum in his right shoulder May 29 while diving back to first base on a pickoff attempt and needed season-ending surgery.
Eovaldi was expected to lose his roster spot because the right-hander will be sidelined next year as he recovers from major elbow surgery and can become a free agent following the 2017 season anyway.
Acquired from the Marlins in a December 2014 trade, Eovaldi was 9-8 with a 4.76 ERA this year.
The 25-year-old Pazos was 1-0 with a 13.50 ERA in seven relief appearances covering 3 1/3 innings last season.
Littell, 21, went a combined 13-6 with a 2.66 ERA in 28 games (27 starts) with two Class A clubs. He had 156 strikeouts and 34 walks in 165 2/3 innings.
The Yankees said Littell will be assigned to Class A Tampa.