Young (8-3) took the loss against the Angels on Thursday, allowing three runs on six hits and two walks in 4.1 innings. He struck out four.
The Royals claimed Little off waivers from the Cubs on Thursday and optioned him to Triple-A Omaha.
The Royals transferred Avila (elbow) to the 60-day injured list Thursday.
Narvaez is absent from the lineup for Thursday's contest against the Angels.
Mayo is not in the lineup for Thursday's game versus the Angels.
The Royals outrighted Velazquez to Triple-A Omaha on Wednesday.
O'Neill went 1-for-3 with a two-run home run in Wednesday's 5-2 win over the Angels.
Mayo went 2-for-4 with a solo home run in a 5-2 win against the Angels on Wednesday.
Rogers (7-7) earned the win against the Angels on Wednesday, allowing two runs on three hits and no walks while striking out nine across six innings.
Kittredge earned the save in Wednesday's 5-2 win over the Angels, when he pitched a flawless ninth with no strikeouts.
