Active rosters expand to 40 players today - both players are on the 40-man roster, and so no corresponding move is required.
Nickeas, 29, hit .364 (24-for-66) with six doubles, one home run and six RBI in 22 games with the Bisons. Nickeas began the year with the Mets and batted .168 (17-for-101) with three doubles, one home run and 13 RBI in 42 games before he was optioned to Buffalo on July 16.
Lutz, 26, hit .299 (73-for-244) with 34 runs scored, 16 doubles, 10 home runs and 35 RBI in 72 games with Buffalo this season. He made his major league debut earlier this year with the Mets going 1-4 (.250) in four games from April 24-29.