When asked if Fowler would be available to travel with the team to Toronto for a three-game series against the Blue Jays beginning Tuesday, Porter wasn't sure.
"When you start talking about a virus running through your body, it takes time," he said. "We don't know how much longer it's going to be. We know the doctors are treating him and we'll see how the rest of [Sunday] goes."
Fowler hasn't played since going 6-for-12 in the Astros' season-opening series win over the Yankees. He went 2-for-4 in each of the three games with two doubles, a triple and a home run, becoming the first player to record at least two runs and two extra-base hits in the first two games of a season since Barry Bonds in 2002.
"He was off to a great start, and we like having that guy at the top of the lineup and manning center field," Porter said. "Not only that, the energy he brings to the ballclub off the field as well is missed in all those areas."
While the Astros have missed Fowler, they're fortunate to have Alex Presley available to play center field in his absence (he started Friday and Sunday). The Astros were going to carry 13 pitchers to enter the season before claiming Presley off waivers just prior to the start of the season in a move that has been beneficial.
"It was definitely something you look at now and had we not made that decision, it would have been very difficult with everything that's happened to Dexter the last few days here," Porter said.
Brian McTaggart is a reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.