Rice has continued his exceptional form for the Hammers into this season, playing every minute of the Irons’ Premier League season except for one game.
Earlier in the season, manager David Moyes insisted that getting Rice for £100m last summer would have been a bargain for any club, but the time for that has passed.
Sinclair thinks West Ham will not be able to finish in the top four and secure Champions League football for next season.
Thus Sinclair thinks that Rice would do well to secure a signing to a club that will play Champions League football next season as he has shown himself more than capable of playing at that level.
Speaking on talkSPORT, Sinclair said: “West Ham for me won’t make the top four this year, not because they won’t try, I just think they will fall short.
“I think Declan Rice has shown a standard of football and performance that he deserves to play in that [Champions League] and he’s ambitious.
“He wants to play in that and I think he’s given everything to West Ham since he’s been at the football club.
“I just feel at the end of the season it might be the right time for him to move and test himself.”
Rice has a contract with the Hammers that extends up to 2024, and time will tell if the Hammers are able to secure Champions League football as well as keep hold of the star midfielder.