Like a child trying not to eat the vegetables, Congress is likely to push Central American issues to the side of its plate next week, hoping they will get cold and go away.

In the case of bills on foreign aid and covert help to Nicaraguan rebels, positions are so firmly drawn that further discussion appears to be a waste of time.

In other cases, including a move to broadcast Cuban news to Cuba, action is likely to be postponed in favor of more pressing issues.

There is also considerable sentiment that military events in the region over the next few months will be far more important than any legislative effort.

According to this view, President Reagan's entire Central American policy--in Congress, with the American public and in the region itself--may hinge on El Salvador's rebuilt army.

If that army can hold recently taken ground in the face of an expected massive counterattack by leftist Salvadoran rebels, it would be impressive evidence to Congress that Reagan's "national strategy" may in time resolve the Salvadoran conflict militarily.

If the army does not hold its own, or if the outcome is indecisive, new questions will arise about the U.S. role in the region.

Reagan's national strategy holds that the United States must help El Salvador erect a "military shield" against guerrilla disruptions and that behind the shield civilian reforms in the economy, the land-ownership structure and human rights may take place.

The "shield" involves the gradual taking and, for the first time, the holding of territory that has changed hands repeatedly during four years of civil war. According to the strategy, the guerrillas would be isolated in small enclaves in a year or two and eventually would be rooted out altogether.

The Salvadoran army has been thoroughly retrained and reorganized at U.S. direction, but it has not faced a major challenge from guerrilla forces. But intelligence sources and State Department officials agree that a series of battles or guerrilla counterattacks are likely soon.

"When the crunch comes, if the government Salvos win, that's the ball game," said a U.S. military adviser instrumental in constructing the national strategy.

But some members of Congress worry that even if the army does appear to be winning, which is by no means guaranteed, there would be a major escalation in support for the rebels from Nicaragua, Cuba and the Soviet Union.

"Reagan thinks he's going to win a great military victory, but that's a delusion," said a top Republican Senate aide. "The only way to avoid a major military escalation is to talk to these people."

A prominent Senate Democratic staff member agreed. "There is a tendency to make the same mistake over and over, to think there'll be a military solution. The best they can hope for is a temporary reprieve," he said.

On the other hand, if guerrilla forces push the Salvadoran government army back, or if they repeatedly launch successful counterattacks in the capital, as they have when pressed in the past, the entire national strategy is likely to be questioned.

"When the illusion of military progress crashes, there'll be a scream for more military aid" from the Salvadoran government, a House Democratic aide predicted.

That means the U.S. role in the area will have to be reassessed, the Republican aide said. "To pursue the same policy then would be ludicrous."

A State Department official with responsibilities in Central America played down this concern, cautioning that military news "will inevitably show reverses and advances" in the short term until "well into next year" when all U.S.-trained units have taken the field.

"Then, if things aren't working it'll be time to call the policy into question," he said.

Meanwhile, Congress will have the opportunity to act on several other issues:

* Radio Marti. The first item of pending Senate business is a proposal to provide $6 million this year and $8.7 million next year for a radio station to broadcast information about Cuba into Cuba. It is one of Reagan's few remaining legislative priorities for Latin America.

Critics argue that the project is an expensive, useless political sop to Cuban-American voters, and that Cuba would retaliate with broadcasts jamming popular radio frequencies in this country.

Yale Newman, associate director of the special State Department office on broadcasting to Cuba, calls that worry "baloney."

He said Cuban facilities do not have sufficient power for long-term jamming and that jamming efforts would also disrupt radio in Mexico, Colombia, Venezuela and other parts of Central America and the Caribbean that Fidel Castro does not want to alienate.

The Senate invoked cloture on one filibuster over Radio Marti, but it may have to deal with a second one by Sen. Lowell P. Weicker Jr. (R-Conn.).

Two House committees have approved Radio Marti; one added crippling amendments that would put it into the Voice of America and surround it with review boards. An eventual Senate vote on an amendment to set up "the VOA option" will probably decide the project's fate.

* Covert aid to Nicaraguan rebels. With the Boland-Zablocki amendment, the House voted overwhelmingly to cut off this aid. It could reaffirm the action with a similar prohibition in the pending intelligence authorization act for fiscal 1984.

However, House leaders are hesitant to push for reaffirmation because any slippage in the vote against covert aid could be interpreted as a softening in sentiment against the Reagan administration's clandestine effort to help topple the leftist Sandinista government.

Chances are even dimmer that the Senate will consider its version of the intelligence authorization act because any House-Senate conference would result in a major battle and the current fiscal year runs out at the end of this month anyway. Intelligence funding is likely to have to depend on a continuing resolution.

The Senate is not likely to discuss Boland-Zablocki.

* Foreign aid. Lacking the stomach for a stiff battle over restrictions on aid to El Salvador, the administration is considered unlikely to call the fiscal 1983-84 foreign aid authorization to the floor of either body. Instead, aid will flow under a continuing resolution as it has for three out of the last four years.

Also moribund in the foreign aid bill is the proposed renewal of the requirement for semi-annual presidential certification of progress in Salvadoran human rights and democratization for U.S. aid to continue. The existing requirement, met for the fourth time last month, expires Oct. 1.

* Immigration. The Simpson-Mazzoli bill approved by the Senate faces opposition and delay in the House. Hispanic and business groups oppose its sanctions against employers who knowingly hire illegal aliens, while labor and civil rights groups are concerned about its provision for a national work card.