JOHANNESBURG, South Africa - In the moment after his collision with England forward Emile Heskey, U.S. goalie Tim Howard grabbed his side and looked as if he might not play another minute in this World Cup.

On Sunday, those worries resurfaced.

One day after the United States's hard-fought 1-1 tie against England, Howard's status became uncertain. U.S. coach Bob Bradley told reporters at the team's compound that Howard was being evaluated with a rib injury and "a decision will be made as to whether he'll need further tests."

Bradley said that he was unsure if Howard suffered broken ribs during the first-half collision, but that an evaluation and perhaps an X-ray or MRI exam would be needed to confirm the extent of Howard's injury.

As of late Sunday night, Howard had not received an X-ray or MRI. He was receiving treatment from the team's training staff and was to be reevaluated on Monday morning to determine if further tests might be needed.

"At this time, there is no answer, but when we see the way Timmy handled himself after the collision, we certainly expect he'll be on the field again," Bradley said optimistically.

On Saturday night as the training staff attended to Howard, backup goalkeeper Marcus Hahnemann began warming up on the sideline. Hahnemann remains the team's secondary option, but Howard's skill and athleticism - on display all game against England - are considered vital to the team's success.

Bradley told reporters that Howard woke up sore on Sunday, which seemed understandable, given the spikes-first collision with Heskey. In Saturday's postgame availability, Howard called the moment "agony."

After lying on the grass for three minutes, visibly pained, Howard remained in goal but grimaced frequently. At halftime, he received a cortisone shot and played without a hiccup in the second half, making a handful of remarkable saves in preserving the United States' tie.

"Obviously he was sore," Bradley said. "He did a great job of taking a tough hit and staying in and playing really well. But we'll assess him later today and figure out what we need to do from there."

Immediately after Saturday's match, question marks began appearing around Howard, who battled valiantly aided by drugs and adrenaline, but who was sure to face an unpleasant wake-up call on Sunday.

The U.S. starters did not train on Sunday, using the day for "regeneration," but the 10 substitutes and two backup goalkeepers practiced, riding the bus to training during the Group C match featuring Slovenia and Algeria and watching as Slovenia notched a late goal to win the match, 1-0.

The United States, England, Slovenia, and Algeria comprise Group C, with Slovenia sitting atop the leader board with 3 points.

The United States plays Slovenia on Friday at Johannesburg's Ellis Park.