The Black and Gold may also be without Diego Rossi, the 2020 Golden Boot winner, who has a hamstring injury.
If either of the former scoring champions are to play, it would be Rossi, as coach Bob Bradley indicated Vela is unlikely to travel to Texas. Vela started the opener but lasted just 20 minutes before missing the Seattle game with his quad injury.
LAFC were linked to a contract extension for the 32-year-old this week when rumours emerged he wanted a return to Spain. Real Betis are courting the former Real Sociedad player in the summer transfer window. A new deal would likely include a raise from his $6.3million salary and could make Vela the highest-paid player in MLS.
Last week LAFC had an early lead but settled for a 1-1 draw in their home showdown with Seattle Sounders. Rossi missed that game, as did defender Tristan Blackmon who is training on his own after being listed on the league's health and safety protocol list.
Houston coach Tab Ramos will be without Sam Junqua and Ethan Bartlow against LAFC, as both suffered concussions last time out. Houston won their opener before losing 2-1 last week against Portland, with the Timbers scoring an own goal to benefit the Dynamo.
LAFC beat Houston 2-1 in the last meeting in October and have never lost to the Dynamo. They have four wins head-to-head and three draws since joining the league in 2017.
Nani leading Orlando City SC
Nani led the Lions to a surprise 2020 season with a runner-up finish at the MLS is Back Tournament and a run to the MLS Cup Playoffs second round. He levelled the match last week in Kansas City with a backheel goal as the Lions earned a point.
In addition to the goal, he led the team with eight duels won, four crosses, and four fouls won. Nani's ability is crucial, with Daryl Dike remaining on loan with Barnsley through the Championship play-offs.
Orlando could have recalled Dike on Monday but announced this week they will allow him to stay at Barnsley through to the end of the season. Dike has nine goals for Barnsley in 18 appearances as the Tykes have jumped to sixth place and a play-off spot for a chance to get to the Premier League.
FC Cincinnati, managed by Jaap Stam, struggled mightily last week. They fell 5-0 to NYCFC and continue to play away from home as their new stadium construction finishes.