Gwynn was scheduled to undergo tests on Monday, according to a published report in San Diego.
The Hogs and Aztecs meet in game one at 6:05 p.m. Thursday. Game two will be at 3:05 p.m. Friday. Saturday's first pitch is set for 11:35 a.m. The Sunday start is set for 12:30 p.m.
"We haven't talked to Tony," said Dave Van Horn, Arkansas coach. "We just got word with an email. I am disappointed for him. I know he looked forward to coming out and seeing our stadium and making this trip, when I talked to him two years ago. I hope he's OK. I don't know the details."
Arkansas and San Diego State met in a four-game series in 2011 in San Diego. This is the return trip for the Aztecs. Arkansas went 3-1 in that series. Both teams enter the weekend with 7-5 records.
The Razorbacks are trying to snap a four-game losing streak from last weekend's trip to Surprise, Ariz. They lost twice to Arizona State and once each to Gonzaga and Pacific to fall from No. 2 to No. 16.
Van Horn said second baseman Dominic Ficociello is doubtful for the weekend, in part because San Diego State goes with mainly righthanded pitching. All of the announced starters for the Aztecs this weekend throw from the right side.
Ficociello is a switch hitter. He has not been able to swing from the left side in games after sustaining a muscle strain in the rib area in preseason. He can swing from the right side. He went three for 10 in four games in Arizona. He's a middle of the lineup hitter for the Hogs.
Ficociello tried to swing from the left side in voluntary workouts Monday, but didn't take any hard cuts. He went two rounds of batting practice Tuesday, again with nothing more than easy swings.
"In the second round yesterday, after the third or fourth swing, he said it didn't feel right," Van Horn said. "I appreciate him being honest. We don't want him to hurt it again. I don't think he did. It just felt tight.
"We'll see how he is in a couple of days, but he may not get in the box again until (the SEC opener) Ole Miss. I don't think it's going to take a long time. But we just want to make sure he gets it well now.
"We feel fortunate that he got to play last week. He still might get in some this weekend, maybe defense. Or if a matchup comes up. We just want him to take a few more days to get better."
Van Horn said the Hogs are ready to get back on the field.
"Losing is definitely a wake-up call," he said. "We've had individual meetings and some group meetings by position. We are trying to get the minds right. Practicing helps. I think they are ready."
The scouting report on the Aztecs sounds familiar to Van Horn. They are loaded with top flight pitching.
"The pitching numbers for them are outstanding," he said. "They have two or three guys who could be weekend starters in the SEC. The Thursday night guy throws 94 to 97. The Friday night guy is 92-94 and he doesn't have an ERA.
"On offense, they are like everyone else in the country, they find a way to get on, get 'em over and get 'em in. It should be a great series."
The opening matchup features UA freshman Colin Poche (1-0, 0.00) against SDSU sophomore righthander Michael Cederoth (1-1, 2.60). Ryne Stanek (1-1, 2.84) goes against SDSU junior righthander Philip Walby (1-1, 1.12) on Friday. On Saturday, it's UA freshman Trey Killian (1.1, 1.29) versus senior righthander Ryan Doran (2-1, 3.32). Lefty Randall Fant (0-0, 2.25) is expected to start on Sunday for the Hogs, but the Aztecs have not announced their last starter.
Van Horn is anxious to see how much the Hogs have improved.
"Last weekend was an incredible learning experience for our players and our coaches," he said. "It's better to do that in nonconference action. The trip was big."
Van Horn said there may be some lineup changes, but he didn't go into details.
"We may go with more left on left situations," he said. "There are some guys that are going to the bullpen. We are still trying to figure it all out."