First baseman Adam LaRoche, who has gone hitless in the series (0-for-7 with three strikeouts) will be replaced at first by Tyler Moore, who will also bat sixth in Johnson's lineup.
Elsewhere, Danny Espinosa is back in the leadoff spot against Tampa's lefthanded starter Matt Moore, while Steve Lombardozzi is back on the bench due to his struggles against left-handed pitching.
Via the @NationalsPR Twitter account.
#Nationals lineup 6/21 vs. #Rays - Espinosa 4, Harper 8, Zimmerman 5, Morse 9, Desmond 6, Moore 3, Nady 7, Flores 2, G. Gonzalez 1
Thursday's game can be seen on MASN and heard on Federal News Radio 1500. First pitch is at 7:05.