Reports today claimed Smalling and his defensive partner Phil Jones will be axed by the Red Devils this summer.
Jose Mourinho wants to sell the United duo and reinvest in his Old Trafford back four.
And according to the bookies, Arsenal are likely to land Smalling, while Everton are the favourites to sign Jones at the end of the season.
BetStars spokesman Ian Marmion said: “Phil Jones and Chris Smalling are on course to leave Old Trafford in the next transfer window as Jose Mourinho looks to upgrade his current defence.
“The Red Devils manager views his backline as the weak link of a side which boasts one of the best goalkeepers in world football and has seen £75m spent on Romelu Lukaku and £89m on Paul Pogba in the last two summers.