Hodgson is upset Vela had to undertake a 12,000-mile round trip for two friendly internationals with Paraguay and Venezuela and did not play a major role in either game.
He told the Birmingham Mail: "I think it is disastrous to have players go away for friendly matches for the length of time it takes to go to Mexico.
"I'm not confident Carlos will come back in the right physical condition.
"I believe he has not played much for Mexico so I think from his personal viewpoint, as a West Brom player, this has been nothing but negative.
"I can't see anything positive about him being away for such a long period of time - but I can't stop him going."
Hodgson does not expect much sympathy from the Mexican FA.
He said: "They make sympathetic noises but then immediately forget you have phoned because they are not interested.
"They're interested in Mexico. They don't care about West Brom and couldn't care less whether we go stay up or go down."